KLF4 and renal cell carcinoma: Decreased or absent KLF4 expression is present in the cancerous part of colorectal carcinoma [7,8], cervical squamous cell carcinoma (SCC) [9], epithelial ovarian cancer [10], pancreatic ductal carcinoma [11], nasopharyngeal carcinoma (NPC) [12], primary lung carcinoma [13,14], bladder cancer [15], gastric cancer [7,16], esophageal SCC [7] and various types of renal cell carcinoma (RCC) [17].