GDF15 and neoplasm: Vascular endothelial growth factor (VEGF) and growth differentiation factor 15 (GDF15) are known to promote tumor growth through coordinating angiogenesis and participating tumor invasion and their expression was enhanced in tumor patients.50,51 It has been reported that the expression of VEGF is inhibited by IFN-γ.52 We found increased expression of VEGF and GDF15 in the group of injection of tumor tissue with patient PBMC which produce less IFN-γ.