PTPN12 and squamous cell carcinoma: A number of studies have reported that decreased expression of PTPN12 as determined by immunohistochemistry was found to be significantly associated with advanced tumor stage in hepatocellular [10, 11], renal cell [12], and urinary bladder [13] as well as in squamous cell carcinoma of the oral cavity, esophagus and nasopharynx [14–17].