CPA7 elicited an inhibitory effect on prostate cancer growth by suppressing STAT3 signaling.21 N‐terminally truncated splice variant of CPE promoted osteosarcoma migration and invasion via the Wnt/β‐catenin pathway.22 However, whether CPA4 functions in tumorigenesis is still unknown. The gene discussed is CPA4; the disease is osteosarcoma.