Antimicrobial peptide gene expression in control and grouper challenged with 1.3 × 106 CFU/ml (20 μl/fish) Vibrio alginolyticus , as determined by qRT-PCR. ( A ) Hepcidin, ( B ) LAP2, and ( C ) Piscidin. Values are presented as the mean ± SEM (n = 5). Values with different letters differ significantly. Significance was set at P < 0.05, as determined by one-way ANOVA followed by Duncan’s test.