In the vaccine ponies, terms such as “regulation of inositol-requiring enzyme 1 (IRE1)-mediated unfolded protein response” (20% of associated genes differentially expressed) could be related to viral infection, while terms such as “positive regulation of steroid biosynthetic process” (13.6% of associated genes differentially expressed) relate to metabolic processes (Figure 6C). Here, ERN1 is linked to viral infectious disease.