The MAST4 Colorimetric Cell-Based ELISA is a convenient, lysate-free, high throughput and sensitive assay kit that can detect MAST4 protein expression profile in cells. The kit can be used for measuring the relative amounts of MAST4 in cultured cells as well as screening for the effects that variuos treatments, inhibitors (ie siRNA or chemicals), or activators have on MAST4.