MAPK1 and glioblastoma: In this phase I clinical trial, the maximum tolerated dose (MTD) of ralimetinib (p38 inhibitor) was 100 mg/12 h, while at the MTD, toxicities of grade ≥3, including hepatic cytolysis, dermatitis/rash, lymphopenia and nausea, was observed with limited activity in GBM patients.