FOXK2 and nonpapillary renal cell carcinoma: For instance, reduced expression of FOXK2 has been linked to tumor suppression in breast cancer (23, 50), cervical cancer (51), glioma (52), gastric cancer (53), ESCC (40), non-small cell lung cancer (NSCLC) (54), and clear-cell renal cell carcinoma (ccRCC) (29), while FOXK2 expression was significantly upregulated in colorectal cancer (17, 41, 42), ovarian cancer (55) and hepatocellular carcinoma (37, 56) (summarized in Table 1).