Bevacizumab (BEV) improves progression-free survival, palliation, and cognitive function in recurrent glioblastoma (rGBM), but overall survival benefits lack strong evidence. BEV combined with lomustine, or radiotherapy is more effective than monotherapy. Better responses are predicted by IDH mutation, large tumor burden, and double-positive signs. Low-dose BEV is as effective as the standard dose, but optimal timing remains unclear. Further studies are needed [61]. This evidence concerns the gene IDH2 and glioblastoma.