IL-17A and IL-17F have been established as the central pro-inflammatory cytokines in colitis (Iwakura et al., 2011; Miossec and Kolls, 2012), though a controversy regarding IL-17A is noted (Ito et al., 2008; Yang et al., 2008; Tang et al., 2018). The gene discussed is IL17A; the disease is colitis.