IGFL4 (human) (rec.) (His)

The Insulin-growth factor-like gene family is a new family of proteins consisting of four proteins in humans (IGFL1 to 4) and one in mice (mIGFL). mIGFL is expressed in normal skin in mice and further upregulated during inflammation responses in the skin or after skin wounding. In humans only IGFL1 expression is increased in psoriatic skin samples. mIGFL and human IGFL1, 3 and 4 interact with specificity and high affinity to a novel receptor named IGF-like family receptor 1 (formerly TMEM-149). Analysis of the amino acid sequence of IGFLR1 indicated that this receptor is likely a novel member of the TNF-R family. IGFLR1 is expressed most abundantly on mouse T cells, suggesting that mIGFL and IGFL1 produced in the skin may potentially exert regulatory functions on T cell responses. In addition to the ovary, spinal cord and fetal skin, IGFL1 is also expressed in head and neck tumors, uterine tumors, squamous cell carcinomas and lung adenocarcinoma. In many cancers, IGFL1 (as well as the other IGFLs) plays multiple roles in regulating the proliferation, differentiation and apoptosis of cancer cells. Biological functions of IGFL4 are not characterized yet.