GI24, also known as platelet receptor Gi24, belongs to the immunoglobulin superfamily. This protein promotes both MT1-MMP expression and the MT1-MMP mediated activation of MMP-2. It supports the differentiation of embryonic stem cells (ESC) and enhances BMP-4 induced in ESC, but it is also down-regulated following BMP-4 exposure. Recombinant mouse GI24, fused to His-tag at C-terminus, was expressed in insect cell and purified by using conventional chromatography techniques.