Expression of IL-8 receptors by HMC-1 cells. (A) CXC receptor expression was measured at the level of message by RPA. In addition to the housekeeping gene product GAPDH (96), a protected fragment for CXCR2 (321) was detected. The two lanes represent two preparations of HMC-1. (B) CXCR2 expression on the surface of HMC-1 cells analyzed by flow cytometry. The bold histogram shows the expression of CXCR2; the thin histogram represents isotype control MoAb. This result is representative of four independent experiments.