ACVR2A and cancer: In the ACVR2 non-expressing primary colon cancers from the original sample size of 51 MSS tumors, 3/7 cancers demonstrated complete methylation (100% methylated alleles) within region 3 of the ACVR2 promoter, while none of the 13 ACVR2 expressing primary colon cancers tissues assayed showed complete ACVR2 methylation, supporting a causative role for methylation and lack of ACVR2 expression (p = 0.03, Fisher's exact test) (Table 2, Figure 3B).