A previous study suggests that Ripk3 promoter hypermethylation underlies the loss of Ripk3 expression in human small cell lung cancer.24 In contrast, we found that demethylating agent and histone deacetylation inhibitor did not enhance RIPK1 and RIPK3 expression in all of the cancer cell lines tested. The gene discussed is RIPK1; the disease is small cell lung carcinoma.