RETNLB and Nematoda infectious disease: It was surprising that the Ws/Ws rats showed a low (or slow) response of Relm-β expression to nematode infection compared to that of Ws/+ rats because the only reported mutation in Ws/Ws rats was a 12-base deletion in the tyrosine kinase domain of the c-kit receptor, which is indispensable for the induction of mast cells by stem cell factor [36].