CXCL1 and squamous cell carcinoma: Therefore, high CXCL1 expression in a tumor cell depends on the action of secretory factors such as basic fibroblast growth factor (bFGF) (lung adenocarcinoma [137,138] and squamous cell carcinoma [138]), IL-17 (lung adenocarcinoma and squamous cell carcinoma) [139], VEGF (lung adenocarcinoma) [137], and thrombin (NSCLC) [137,140].