TNF and cancer: PCC-conditioned medium activated p38 MAPK and p38β MAPK effector C/EBPβ in one hour, consistent with previous findings from immortalized cancer cells [21,29,35], suggesting that this action involved Hsp70 and Hsp90 receptor TLR4-mediated post-transcriptional modifications independently of the cancer-induced systemic increase of inflammatory cytokines [17,19] that can activate p38 MAPK including IL-6 [39], TNFα [40], IL-1 [41], and activin [10,20].