GeronĀ (NASDAQ:GERN) shareholders got some welcome news at last with the lift of the partial clinical hold on imetelstat for myelofibrosis. So is now the time to buy the stock?

Not so fast. There's still a clinical hold for polycythemia vera and multiple myeloma. And imetelstat is still in phase 2 trials -- so commercialization is still some ways away. It's not that the stock is necessarily a bad investment -- it's that there's still too much uncertainty to be sure that it's a good investment.

In the video below, fromĀ Market Checkup, health care analysts Michael Douglass and David Williamson lay out why Foolish investors should still avoid Geron's stock.