In carp (Cyprinus carpio) after infection with Aeromonas salmonicida subsp., it was shown that in autumn, the expression of inos, il-12p35, ifn-γ2, and arginase 2 was increased, while in spring, inos, il-12p35, ifn-γ2, arginase 2, and il-10 were positively regulated, in addition to crp2 at 96 hpi (hours post-infection), evidencing a seasonally differentiated immune response [18]. Here, ARG2 is linked to infection.