(E)-4-Hydroxy-3-methyl-but-2-enyl pyrophosphate (HMBPP or HMB-PP) is an intermediate of the  MEP pathway (non-mevalonate pathway) of isoprenoid biosynthesis.
The compound (E)-4-Hydroxy-3-methyl-but-2-enyl pyrophosphate, also known as HMBPP or HMB-PP, serves as a key intermediate in the MEP pathway, which is an alternative route for producing isoprenoids.