PRLR and Familial prostate cancer: Prolactin receptor (PRLR), which was suggested as a therapeutic target in subgroups of breast and of prostate cancer,26 was overexpressed in ERRB2-Ex20mut and EGFR-Ex18/19/21mut tumors compared to EGFR/ERBB2wt tumors (FC = 8.2, P = 0.00028 and FC = 4.3, P = 0.0012).