Since RD3 expression is thus far unknown in normal human tissues other than the retina and is critical to defining its role in cancer biology, we examined the expression and localization of RD3 protein in the retina, central nervous system (brain, spinal cord, and olfactory bulb), gastrointestinal tract (esophagus, stomach, duodenum, appendix, colon), pancreatic hepatobiliary tract (parotid and submandibular gland, liver, bile ducts, pancreas), and other organs (lung, kidney, placenta, uterus, thymus, prostate skin, fallopian tube, thyroid, tonsil, breast). The gene discussed is RD3; the disease is cancer.