CD274 and meningioma: Clinical trials are currently underway for checkpoint inhibitors in meningioma patients (nivolumab and ipilimumab; NCT02648997, NCT03279692, and NCT03173950, pembrolizumab NCT03016091, avelumab NCT03267836) which include targeting the PD-1/PD-L1 axis previously suggested for VS [20, 45, 46].