The transcriptomic data also showed that PER2 was upregulated, while G6PD and SIRT2 expression was downregulated in GBM cell lines after metformin treatment (Figure 4F), which sparked our intense interest to investigate what happened to G6PD, SIRT2, PER2, and metformin in the PPP signaling pathway. The gene discussed is SIRT2; the disease is glioblastoma.