G6PD and viral infectious disease: In the absence of a functional G6PD enzyme, viral replication becomes easier in several viral infections.32,33 Molecular studies have shown that a protein named HSCARG, which is an NADPH sensor and negative regulator of nuclear factor kappa light chain enhancer of activated B cells (NF-κB), gets upregulated in G6PD deficient cells resulting in a decreased NADPH/NADP+ ratio.