The results showed that silencing SPHK1 gene significantly decreased cell viability (Fig. 5B) and increased apoptotic index in GBM cells with TMZ treatment (Fig. 5C), suggesting that silencing SPHK1 gene in both LN229 cells and U87MG cells increased the efficacy of TMZ killing and sensitivity of TMZ treatment. The gene discussed is SPHK1; the disease is glioblastoma.