In the current study, we performed a pan-cancer investigation of CCND1 expression, methylation, prognosis, immune infiltrations, genetic alteration, survival, and differentially expressed genes (DEGs) across tumors using GEPIA, UALCAN, TIMER, GSCA, cBioPortal, GEO, and UCSC Xena databases, and Kaplan-Meier plot. Here, CCND1 is linked to cancer.