The relative expression of Cctlr19 in the HKL of common carp after treatment with poly(I:C). (A), LPS (B), PGN (C) and flagellin (D) at different time points. The results were calculated relative to the expression of the 40S ribosomal protein S11 gene. The data are presented as a fold increase compared to the unstimulated control group (denoted by 0 h). Means ± SD (n = 3), *P < 0.05, **P < 0.01, ****P < 0.0001, one-way ANOVA.