It is discovered that PIK3CAH1047R mutant DNA in colorectal cancer (CRC) cell‐derived exosomes can be delivered into recipient fibroblasts, where they are transcribed and translated, ultimately leading to the activation of fibroblasts into cancer‐associated fibroblasts (CAFs) through interaction with the endogenous P85 regulatory subunit of the phosphatidylinositol 3‐kinase (PI3K) pathway. This evidence concerns the gene PIK3CA and cancer.