IL4 and macrophage activation syndrome: This was consistent with the IL-4 treated RαTd/Td mice exhibiting characteristics of macrophage activation syndrome, associated with splenomegaly and erythrophagocytosis (38). To further analyze and validate some of these genes and their association with RELMα at the single cell and protein level, we use t-SNE mapping of flow cytometry data of peritoneal cells (Figure 4D).