We found that infiltration of macrophages, dendritic cells, CD4+ T cells, CD8+ T cells, neutrophils, and B cells were positively correlated with STAT3/CDK2/4/6 expressions in lung adenocarcinoma, liver hepatocellular carcinoma, head and neck cancer, and breast invasive carcinoma cohorts, suggesting that CDK2/4/6/STAT3 may also reflect the immune status besides the disease prognosis. Here, CDK2 is linked to lung adenocarcinoma.