Zhong H, et al. - This study including house dust mite (HDM)-allergic allergic rhinitis (AR) patients investigated the Group 2 innate lymphoid cells (ILC2) levels in the peripheral blood of these patients, along with their ability to secrete type 2 cytokines. Findings indicated a crucial role of ILC2 in AR patients. In these patients, an increased number of ILC2s was detected and ILC2s produced the amount of T helper type 2 (T_H2) cytokines in the presence of epithelial cytokines.