Six of the genes (CASP1, CCL2, ADGRE5, IL3RA, RSPO1, and STAB1) are co‐expressed with the CH25H gene in both cancers, while two genes (ANPEP in breast cancer and CCL8 in prostate cancer) are exclusively co‐expressed with the CH25H gene in one of the tumors. The gene discussed is RSPO1; the disease is breast cancer.