ANXA5 and thyroid cancer: When we analyzed Obatoclax-treated mouse thyroid cancer cells, we found that this compound induces massive necrosis (TOPRO3 and Annexin V double positive cells) as early as 6 hours after treatment, peaking between 24 and 48 hours, with no apoptotic (TOPRO3 negative and Annexin V positive) component (Figure 1E).