EpoR probe validation in human pancreatic tissue. A, A section of human pancreatic tissue with sense RNA probes for EpoR. B, Same tissue with anti-sense RNA probes for EpoR, demonstrating increased expression in islet of Langerhans cells. C, A section of human pancreatic tissue showing a vein adjacent to an acinar cell, with sense RNA probes. D, The same tissue with anti-sense RNA probes for EpoR, demonstrating expression in the endothelium of the vein (arrows). Abbreviations: ac, acinar cells; ar, artery; isl, islet of Langerhans.