In vivo allergic responses in pigs are increased by ATRA in response to parasitic infections including increased lung eosinophilia and expression of Th2-associated cytokines, interleukin 4 (IL-4) and IL13, eosinophil chemo-attractants (Chemokine (C-C motif) ligand 11 (CCL11), CCL22, CCL17, and CCL26) and the goblet cell differentiation marker, chloride channel, calcium activated, family member 1 (CLCA1) (7). This evidence concerns the gene IL4 and parasitic infectious disease.