PTGDS and allergic disease: Although many immune-relevant genes were also found among downregulated genes, they also included prostaglandin D2 synthase (Ptgds) and prostaglandin D2 receptor (Ptgdr), which are involved in allergic reactions; granulysin (Gnly), which is expressed in activated cytotoxic T cells (CTL) and NK cells; and Janus kinase 1 (Jak1) and RAR-related orphan receptor A (Rora), which are related to T-helper 17 cells (Th17).