SULF1 and squamous cell lung carcinoma: Recent studies revealed that different types of tumors present an increase in SULFs expression, including: hepatocellular carcinoma [27], pancreatic cancer [28], squamous cell carcinoma of the head and neck [29], gastric cancer [30], lung adenocarcinoma and squamous cell carcinoma of the lung [31] for SULF1 and hepatocellular carcinoma [32], lung adenocarcinoma and lung squamous cell carcinoma [31] for SULF2.