Tumour-related cell death can be regulated through autophagy [51] and apoptosis [52] by targeting PRL/PRLR, while the combination of PRL and PRLR has a dose–response relationship: a low concentration of PRL promotes the secretion of PRLR, whereas a high dose of PRL inhibits PRLR [53]. The gene discussed is PRLR; the disease is neoplasm.