Recently, several reports using mice with C57BL/6 background infected with the Tulahuén strain showed that Th17 high levels conferred protection against infection using Il-23 inhibitory BATF2 (Kitada et al., 2017), regulatory EBI3 (Böhme et al., 2016), IL-17A (Miyazaki et al., 2010) and IL-17RA (Tosello Boari et al., 2012) deficient mice. The gene discussed is IL17A; the disease is infection.