Verastem believes the truth behind recurrent tumors lies in cancer stem cells (CSCs), aggressive tumor cells that survive conventional treatment to cause recurrence. Those CSCs are the target of its biopharmaceutical R&D efforts; the company is working to produce small molecule drugs that target the cells while conventional therapy targets the rest of the tumor. Verastem's work rests on a technology, licensed from MIT's Whitehead Institute, that allows it to create stable CSCs in the lab, something not possible in the past. Its leading drug candidate targets a type of breast cancer with a low survival rate. The company is also developing CSC diagnostics. Formed in 2010, Verastem filed to go public in late 2011.