Interestingly, in WSSV group, the abovementioned changes were not consistent with time and in the majority of cases the expression level of one gene in the late stage of infection (i.e. 56 hpi) markedly differed from the expression level in the early-middle stage of infection (i.e. 1.5 and 18 hpi): for example, this difference was found in the majority of metabolic, apoptotic or ABC transporter genes. This evidence concerns the gene ABCG2 and infection.