FOXP1 and prostate cancer: It is also frequently downregulated in solid tumors, including breast cancer [61–63], non-small cell lung cancer [64], oral squamous cell carcinoma [65], ovarian cancer [66, 67], renal cell carcinoma [68, 69], hepatocellular carcinoma [70] and prostate cancer [71–73], which suggests that FOXP1 may act as a tumor suppressor.