In our experiments, the treatment of A-172 glioblastoma cells for 24 and 48 h with sorafenib led to an increase in the expression of mRNA of the spliced form of the XBP1s transcription factor and did not change the expression of two other markers of ER-stress, ATF-4 and ATF-6 (Figure 7A,B). Here, ATF4 is linked to glioblastoma.