Therefore, we used NK cells that were expanded and activated according to the previously established protocol by using a feeder cell, K562 expressing the OX40 ligand and membrane-bound IL-18 and IL-21, which showed potential effects on multiple myeloma in the previous study (23); we wanted to confirm the therapeutic effects of these established NK cells in the GBM setting. Here, TNFRSF4 is linked to glioblastoma.