HK2 and metabolic disease: Interestingly, 4-OP induced energy metabolism disorder, as evidenced by the decrease in four ATPases (Na+K+-ATPase, Ca2+Mg2+-ATPase, Ca2+-ATPase, and Mg2+-ATPase), the increases in four glycolytic enzymes (HK1, HK2, LDHA, and PGK1), the decrease in glycolytic enzyme PGAM2, and the increase in energy sensor AMPK.