GHRL and schizophrenia: Three less common substrate-specific lipidation subtypes of interest in schizophrenia research are N-palmitoylation and cholesterylation of Hedgehog (Hh) proteins,15–18 and octanoylation of ghrelin.15,16,19 Comprehensive reviews of multiple types of protein lipidation, including detailed information about the enzymology, substrates, and biochemistry of fatty acid and isoprenoid lipidation of proteins, as well as some other less common lipid PTMs, have been recently published.14–18