In conclusion, our findings, for the first time, estimated the expression of thymic cortical (β5t, PRSS16, and cathepsin V) and medullary epithelial markers (AIRE, CD40, and claudin-4) in differential diagnosis, Masaoka-Koga stage, histological classification, and prognosis of thymic tumors. This evidence concerns the gene CTSV and thymus neoplasm.