IL4 and asthma: This is consistent with speculation in the literature that iNKT cells participate in human asthma by altering their phenotype rather than their frequencies: for example, although asthma patients and controls do not differ in terms of iNKT-cell frequencies in the BALF, the asthma iNKT cells express more IL-4 (Akbari et al., 2006; Shim and Koh, 2014).