IL1RL1 and asthma: Nonetheless, GITR expression levels on ILC2s are associated with asthma: RNA-sequencing analysis of lung ILC2s from Alternaria-treated mice showed that the expression of GITR in ILC2 populations correlated strongly and positively with their expression of ILC2 signature molecules (Il1rl1 (encoding ST2)) and type 2 cytokines (Il5 and Il13)112.