The Prostate Apoptosis Response protein-4 Colorimetric Cell-Based ELISA Kit is a convenient, lysate-free, high throughput and sensitive assay kit that can detect ProstateApoptosisResponseprotein-4 protein expression profile in cells. The kit can be used for measuring the relative amounts of ProstateApoptosisResponseprotein-4 in cultured cells as well as screening for the effects that variuos treatments, inhibitors (ie siRNA or chemicals), or activators have on ProstateApoptosisResponseprotein-4.