TLR9 and inflammatory bowel disease: Our RT‐qPCR results showed that TLR signaling‐related genes (tlr3, tlr4, tlr5, tlr7, tlr8a, tlr8b, tlr9, tab1, tbk1, nf‐κb, myd88, irf3, irf5, irf9), necroptosis signaling‐related genes (tlr3, tlr4, trif, ripk1, ripk3, caspase‐8, fadd, bax, bcl2), and inflammatory factors (tnf‐α, tnf‐β, il‐4, il‐6, il‐8, il‐10, il‐12, caspase‐1, cox‐2) were aberrantly expressed in zebrafish with IBD.