These trials include a Phase I/II clinical trial (NCT01952769) to study the safety and efficacy of Pidilizumab in diffuse intrinsic pontine glioma and relapsed GBM, a Phase II trial of neoadjuvant Nivolumab in primary and recurrent GBM (NCT02550249), a Phase II trial of Pembrolizumab in recurrent GBM (NCT02337686), and several trials examining the effects of combination therapy of anti-PD-1 antibodies with Temozolomide with and without radiation therapy (NCT02311920, NCT02530502), INCB24360 (NCT02327078), FPA008 (NCT02526017), and dendritic cell vaccine (NCT02529072). Here, PDCD1 is linked to glioblastoma.