IHC staining of normal and prostate tumor sections revealed that CEACAM20 was expressed on the luminal surface of prostate glands (21/22 of normal prostate and 17/17 of prostate tumors with Gleason grade ≤3) but its expression was absent in prostate tumors with a Gleason grade ≥4 (6/6) lacking lumina (Fig. 1C and Fig. 1D). The gene discussed is CEACAM20; the disease is prostate neoplasm.