In RPE cells, we suppose that cAMP leads to the activation of protein kinase A, which in turn opens L-type Ca2+ (e.g., CACNA1A: 3.85 mFPKM; CACNA1A: 2.63 mFPKM) (Rosenthal and Strauss, 2002) or TRP channels (e.g., TRPM3: 1.71 mFPKM; TRPM4: 7.76 mFPKM), as shown in epidermal melanocytes and prostate cancer cells (Spehr et al., 2011; Gelis et al., 2016). The gene discussed is TRPM4; the disease is prostate cancer.