PI4K2A and centronuclear myopathy: The conversion of nutrient-signaling active anabolic to degradative catabolic lysosomes in starved cells in addition to PI4K2A also involves hydrolysis of lysosomal PI(3)P by the PI 3-phosphatase MTMR14 (64), another enzyme mutated in an autosomal form of myotubular myopathy (129), suggesting that altered lysosome function may contribute to inherited forms of myotubular myopathy.