The expression of IL-1β in the embryo tail fin was not related to the experimental infection because GFP is constitutively expressed in Tg(Il-1b:GFP-F+/+) embryos after 50 h post fertilization in keratinocytes at the tip of the caudal fin and in fin buds, retina, neuromasts, gills, and thymus (Nguyen-Chi et al., 2014). The gene discussed is IL1B; the disease is infection.