Recent studies demonstrated that epigenetic activation of Wnt signaling (marked by enhanced β‐catenin and silent RNF43) is prevalently observed in multiple types of cancer.47, 48, 49 Reduced methylation of PTEN CpG islands suppresses, while hyper‐methylation of PTEN CpG islands stimulates PI3K‐Akt signaling.50, 51 Methylation of CDH1 CpG islands also increases in malignant tissues and contributes to tumorigenesis.52, 53 Nevertheless, RNA methylation is merely reported to be involved with these pathways. This evidence concerns the gene PIK3CA and cancer.