By contrast, apaf1 gene expression was the most significantly increased after CDK8 knockdown together with IR treatment compared with IR treatment or CDK8 knockdown alone (Figure 3B and Supplementary Figure S1), indicating that the intrinsic apoptotic pathway induced by IR treatment in CDK8 knockdown CRC cells was triggered by apaf1. The gene discussed is APAF1; the disease is colorectal carcinoma.