HSPA5 and glioblastoma: Moreover, in both U87 and U251 glioblastoma cells, wogonin exposure increased the expression of GRP‐78, GRP‐94, calpain I, eIF2, and other endoplasmic reticulum stress markers, along with caspase‐9 and caspase‐3, ultimately resulting in ROS generation and cellular death (Tsai et al. 2012).