Flow cytometric analysis revealed that the number of CTLs following allogeneic HSCT was higher compared with syngeneic HSCT on days 20 and 27 (Fig. 3E–G), indicating that despite the number of CTLs following transplantation not completely recovering to a normal level, the IFN-γ secreted by T lymphocytes following allogeneic HSCT may promote the expansion of CTLs and exert a suppressive effect on cancer. Here, IFNG is linked to cancer.