HLFs were treated with control or AHR specific siRNA #2 for 48 hours and then exposed to DMSO or HpCDD at doses indicated for 24 hours. After treatments, Let-7d (A), miR-103 (B), and miR-144–3p (C) were detected by RT-qPCR. AHR siRNA significantly attenuated the effect of 1 nM HpCDD for all 3 miRNAs. At 200 pM HpCDD, AhR siRNA significantly attenuated the reduction in miR-144–3p. The experiment was performed in 2 different HLF strains in quadruplicate with similar results in both strains. Representative data from 1 strain presented as means ± standard error, * = p < 0.05, ** = p < 0.01, Two-way-ANOVA.