Cyclic GMP-dependent protein kinase type I (cGKI) exerts a cytoprotective function, as cGKI-deficient mice exhibit anemia and splenomegaly due to accelerated erythrocyte clearance—underscoring cGKI’s capacity to buffer pro-eryptotic signals (Föller et al., 2008a). The gene discussed is PRKG1; the disease is Splenomegaly.