Tumor-derived IgG, whose expression was induced by androgen-deprivation therapy and upregulated by SRY (sex-determining region Y)-box 2 (SOX2) in prostate cancer cells such as C4-2 and DU145, promoted the migration and invasion ability of prostate cancer cells through mitogen-activated protein kinase/extracellular signal-regulated kinase and AKT and EMT. Here, SRY is linked to Familial prostate cancer.