Definition of Isoform

Isoform: A protein that has the same function as another protein but which is encoded by a different gene and may have small differences in its sequence. For example, transforming factor beta (TGF-B) exists in three versions, or isoforms (TGF-B1, TGF-B2, and TGF-B3), each of which can set off a signaling cascade that starts in the cytoplasm and terminates in the nucleus of the cell.


Last Editorial Review: 6/14/2012

Search MedTerms:


Back to MedTerms online medical dictionary A-Z List
Pill Identifier Tool

Need help identifying pills and medications?
Use the pill finder tool on RxList.