Illumina (ILMN -0.70%) did it again. 

The gene-sequencing leader made 2017 a year to remember, thanks in large part to a strong launch of its new NovaSeq system. On Tuesday, Illumina's first-quarter earnings results showed that 2018 is likely to be an even better year. The company beat Wall Street estimates on both the top line and the bottom line. Illumina also upped its full-year 2018 guidance for revenue and earnings.

But Illumina's first-quarter earnings release didn't reveal everything you need to know. Here are the three biggest stories that the company's earnings update didn't tell (quotes courtesy of S&P Global Market Intelligence). 

Illumina headquarters

Image source: Illumina. 

1. Sequencing consumables 

Illumina's first-quarter earnings release didn't provide any details on sequencing consumables revenue. CEO Francis deSouza's comments in the release didn't mention consumables at all. But during Illumina's earnings conference call, it was clear that the biggest story behind the company's first-quarter success was strong sequencing consumables growth.

It's important to note that consumables for Illumina's high-throughput HiSeq gene-sequencing systems fell $20 million from the fourth quarter of 2017. However, NovaSeq consumables growth more than offset that decline. DeSouza said in the conference call that consumables across Illumina's high-throughput systems, which include NovaSeq and HiSeq, increased 34% year over year. NovaSeq consumables sales soared 60% higher than 2017 Q4 levels, adjusting for a $19 million stocking order in the fourth quarter.

The company didn't only see growth from its high-throughput systems, though. Consumables revenue for Illumina's NextSeq system increased 40% year over year.

DeSouza stated that the "trajectory of our sequencing consumables business is very exciting." He's right. Consumables revenue is passive revenue for Illumina: The company doesn't have to do very much for the money to pour in the door. That's what every business would like to have. And for Illumina, it's becoming a greater source of total revenue.  

2. Consumer genomics

Francis deSouza did mention growing adoption of consumer genomics in his statement in Illumina's first-quarter earnings announcement. However, that brief reference didn't give the full picture of how important this business is for Illumina.

Consumer genomics, sometimes called personal genomics, includes the genetic services marketed directly to consumers by companies such as Ancestry, 23andMe, and Illumina's own spin-off, Helix. These consumer genomics companies use Illumina's microarrays for analyzing the DNA of their customers.

Increased demand for consumer genomics helped drive Illumina's microarray revenue up 48% year over year in the first quarter. Microarrays now contribute 19% of total revenue, up from 16% in the fourth quarter of 2017.  

The consumer genomics business should get a big boost from FDA approval for 23andMe's direct-to-consumer genetic tests for cancer risk. The health reporting component of consumer genomics appears likely to grow tremendously. 

Consumer genomics is also expanding globally. DeSouza stated that Illumina picked up a new customer in April, WeGene, that will offer consumer DNA testing in China. He continues to believe that the consumer genomics market reached "an inflection point" last year and remains in a very early stage of adoption.

3. Early stages of major long-term growth drivers

Perhaps the biggest story of all for Illumina is that the company has several major long-term growth drivers in their early stages. Consumer genomics is only one of them.

DeSouza noted that there's "a huge amount of interest in immuno-oncology." This includes growing interest in development of liquid biopsies for early detection of cancer. Illumina recently announced two oncology deals, one with Bristol-Myers Squibb to develop in-vitro diagnostic (IVD) assays for the company's cancer drugs and another with Loxo Oncology to develop a multigene panel for tumor profiling. 

It's also still very early for NovaSeq, even though the system has been on the market for more than a year. At the end of 2017, only around 15% of Illumina's HiSeq and HiSeq X customers had bought a NovaSeq system. That percentage is higher now after the first quarter, but Illumina should enjoy several more years of sales growth for NovaSeq.

The company's other new system, iSeq, is still in beta testing. DeSouza said that Illumina is seeing "strong interest in iSeq" with nearly 100 orders for the low-cost system already. With a price tag less than $20,000, Illumina anticipates that iSeq could attract more than 50,000 customers, including 35,000 who are new to next-generation sequencing.

Potential speed bumps

What could get in the way of Illumina's momentum? The stock probably wouldn't be immune to an overall market correction. It's possible that the transition of existing HiSeq customers to NovaSeq could see ups and downs, resulting in Illumina occasionally missing analysts' earnings estimates. And while governments across the world are opening up their purse strings now to fund genomic-sequencing efforts, that could always change.

In my view, though, any of these possible issues for Illumina should be only speed bumps for the company. They might slow Illumina down temporarily, but they won't be roadblocks that keep it from moving forward.

Francis deSouza said, "Genomic information is more valuable and actionable than ever before, and we believe that we are in the earliest stages of a genomics revolution." That's a pretty good summary of the long-term prospects for Illumina.