Consistent with our ISRIB studies, NXP800 had limited to no impact on eIF2α phosphorylation and ATF4, ATF6 and IRE1 protein expression, or effects on AR, E2F and MYC in our NXP800-resistant 22Rv1 prostate cancer subline, further supporting that activation of the eIF2α axis plays a role in the NXP800-mediated phenotype observed. This evidence concerns the gene ATF4 and prostate cancer.