SREBF1 and sarcoma: In addition, the nuclear form of SREBP-1 (nSREBP-1) can bind to the promoter of protein kinase RNA-like endoplasmic reticulum kinase (PERK) to augment its expression and phosphorylation, which might be the main reason that nSREBP-1 regulates cell proliferation, cell cycle arrest, apoptosis, and autophagy under endoplasmic reticulum (ER) stress in sarcomas (chondrosarcoma and osteosarcoma) (134).