In addition, Xi et al. reported that melatonin may suppress the prostate cancer cell (LNCaP cell) through the melatonin receptor (MT1 receptor) with attenuated calcium influx, which activates protein kinase C to inhibit the PSA gene (KLK3 gene), consequently decreasing PSA levels [42,43]. The gene discussed is KLK3; the disease is prostate carcinoma.