<h4>Background</h4>ATF3 was found to play a complex role in various cancers; however, its systematic function in kidney renal clear cell carcinoma (KIRC) and across pan-cancer contexts remained incompletely understood.<h4>Methods</h4>A comprehensive evaluation of ATF3 expression, diagnostic efficacy, prognostic relevance, and its association with the tumor immune microenvironment was conducted across multiple cancer types using publicly available databases. The gene discussed is ATF3; the disease is cancer.