DDIT3 and squamous cell carcinoma: In another report, BCl inhibited the proliferative activity of human laryngeal (UMSCC23) and tongue (HN12) squamous carcinoma cells, by inducing a terminal unfolded protein response (UPR), which led to the up-regulation of the transcription factor CCAAT-enhancer-binding protein homologous protein (CHOP) and subsequently to CHOP-dependent apoptosis [160].