Furthermore, HSChigh glioblastoma samples associated with the expression of immune checkpoint molecules, including PD-1 (PDCD1, p = 2.7 × 10−4), PD-L1 (CD274, p = 0.016), and PD-L2 (PDCD1LG2, p = 0.003) (Fig. 6g). Here, PDCD1 is linked to glioblastoma.