HMGCS1 and cancer: Moreover, in agreement with the MVA pathway being regulated by the EWSR1-FLI1/EGR2 axis, the global expression of 16 MVA pathway enzymes, and specifically the 2 rate-limiting genes HMGCR and HMGCS1, was significantly higher in Ewing cell lines as compared with other cancer cell lines (Figure 3B and Figure S2A).