Several studies have identified KIF11/Eg5 as overexpressed at the RNA and protein levels in both NSCLC and SCLC compared to normal tissues, with high expression correlating with greater pathological stage, lymph node metastasis, and poor progression-free and overall survival rates [41,55,56,57,58,59,60,61,62,63]. Here, KIF11 is linked to small cell lung carcinoma.