H6PD and neoplasm: Moreover, Huanhuan et al. [144] examined the effect of caffeine in the inhibition of renal cell carcinoma (RCC) and showed that caffeine may target glucose-6-phosphate dehydrogenase (G6PDH), inhibit G6PDH activity, and disrupt redox homeostasis, and through this, may inhibit RCC tumor growth, which is dependent on G6PDH activity.