In particular, in OI, mutant collagen is retained within cells, leading to increased autophagy: osteoblasts derived from COL1A1 mutant mice display increased levels of lysosomal markers responsible for collagen degradation, suggesting the upregulation of autophagy, aimed at coping with aberrant collagen accumulation [30]. The gene discussed is COL1A1; the disease is osteogenesis imperfecta.