In recent years, gene editing technologies (CRISPR/Cas9, TALEN, ZFN) have contributed to addressing GvHD and HvGA by knocking out TCR on allogeneic CAR-T along with MHC-I/B2M, thus improving the anti-tumor effectiveness of CAR-T cells (89–94) (Table 2). Here, B2M is linked to neoplasm.