Of note, PIK3R1 mutations were noted in 25 of 256 (10.0%) glioblastomas; however, these mutations were not significantly associated with shorter PFS (median 6.2 months vs. 8.5 months, p = 0.14) or OS (median 13.7 months vs. 13.3 months, p = 0.73). Here, PIK3R1 is linked to glioblastoma.