In vivo co-IF staining for PHGDH and 8-OHdG in GSC-derived xenografts and human GBM specimens revealed lower 8-OHdG levels in high PHGDH-expressing tumor cells, indicating PHGDH’s protective effect against oxidative DNA damage (Fig. 3K, N, Supplementary Figure S4I). Here, PHGDH is linked to neoplasm.