Both molecules are involved in immune regulation: B7-H3 preferentially dampens Th1-mediated responses (Suh et al., 2003), whereas ICOSL promotes IL-10 secretion by T cells (Witsch et al., 2002) and induces Tr1 cells that produce IL-10 and inhibit experimental airway inflammation in mice (Akbari et al., 2002; Conrad et al., 2012). This evidence concerns the gene IL10 and inflammation.