CASP2 and infection: Several recent studies found that caspase and caspase 4 of F. merguiensis, caspase 2 of L. vannamei and caspase 1 of P. monodon were all up-regulated in the hemocytes after DIV1 infection (Liao X. et al., 2020; Liao X. Z. et al., 2020; He et al., 2021).