ATG7 and osteogenesis imperfecta: In a murine model of OI, osteoblasts were found to undergo ER stress-mediated apoptosis from inadequate collagen processing and secretion, but 4-PBA treatment alternatively promoted postnatal bone growth and reduced facture incidence.210 Furthermore, generation of osteoblast-specific ATG7 conditional knockout mice revealed reduced bone mass resulted from impaired osteoblast formation and matrix mineralization.211 Treatment with 4-PBA was found to ameliorate ER stress triggered in ATG7-deficient osteoblasts and restored function similarly to that seen in OI defective osteoblasts.210,211