Alecu et al. [29], Patocka [30], Kusari et al. [31] and Xu and Leung [32] also demonstrated that hypericin, another important component of SJW, inhibited the growth of glioma cells in vitro and was also capable of inducing cell death through the inhibition of protein kinase C (PKC), which regulates the formation and growth of tumors. This evidence concerns the gene PRRT2 and central nervous system cancer.