KRAS and pachyonychia congenita: PC cancer cell changes regulate the quantity and quality of mitochondria to better adapt to hypoxic, low pH, and nutrient-deficient microenvironments: on the one hand, KRAS induces mitophagy and reduces the total number of mitochondria via accumulation of one kind of protein called NIX, with the aims of eliminating excessive intracellular reactive oxygen species (ROS) and providing nutrient metabolites (e.g., glucose and glutamine) to support cell proliferation [31].