In vitro and in vivo experiments demonstrated that melatonin suppresses FOLH1 expression in a concentration-dependent manner, inhibits invasive and migratory capacities, and restricts tumor growth under physiological circadian melatonin levels.<h4>Conclusion</h4>This study highlights FOLH1's pan-cancer expression patterns and nominates melatonin as an exploratory therapeutic candidate for prostate cancer requiring further mechanistic validation. Here, FOLH1 is linked to neoplasm.