MCAM and small cell lung carcinoma: Melanoma cell adhesion molecule (CD146/MCAM), which was originally discovered in melanoma cells [1], is a transmembrane glycoprotein of the immunoglobulin superfamily that is present in many tumors, such as melanoma, the pancreas, prostate, breast, kidney, ovarian cancer, mesothelioma, and small cell lung cancer [1,2,3,4,5,6,7].