LRIG1 protein is coded by a gene on a chromosome band 3p14.3, a region known to be deleted in various human cancers. It is considered to be a tumour suppressor gene. LRIG1 is an integral cell-surface membrane protein that is expressed by specific cells in various human tissues. Its 143kDa form may be cleaved into 111kDa and 32kDa fragments. The protein may inhibit the growth of tumors of glial cells and the down-regulation of the LRIG1 gene may be involved in the development and progression of the tumor.