RB1 and combined immunodeficiency: To further explore whether blocking CD47 enhances the therapeutic antitumor response in vivo, we subcutaneously transplanted GCT cells (5 × 106 cells per mouse) isolated from four-month-old Rb-DKO females to severe combined immunodeficiency (SCID) mice (T cell-, NK cell-, and B cell-deficient) to establish a heterotopic GCT model.