This model describes farnesyl-diphosphate farnesyltransferase, also known as squalene synthase, as found in eukaryotes. This family is related to phytoene synthases. Tentatively identified archaeal homologs (excluded from this model) lack the C-terminal predicted transmembrane region universally conserved among members of this family.
Jiyao W et al.(2023). "The conserved domain database in 2023.",