HTRA2 and cancer: Proteases such as ubiquitin specific peptidase 30 (USP30), presenilin associated rhomboid like (PARL), and HtrA serine peptidase 2 (HTRA2) in the UPRmt can interact with mitophagic regulator PINK1-Parkin, and then inhibit mitophagy and maintain mitochondrial proteostasis in cancers [142].