HMGCS1 and eosinophilia-myalgia syndrome: In order to figure out the underlying mechanism behind PrPC aggravating EMs severity, the next RNA-Sequencing assay was performed between control (CON335) and PRNP overexpressed (LV-PRNP) HESC, and we found out that transcription of cholesterol metabolism related genes significantly changed, with expression of cholesterol biosynthesis related genes (e.g. HMGCR, HMGCS1, MVK and FDPS) being activated and level of cholesterol efflux (e.g. ABCA1) and transport (e.g. RXRA and APOE) related genes being inhibited (Figure 5A).