“…Although some groups claim to find expression of HLA-DR in normal colorectal epithelium in humans (McDougall et al, 1990;Tsioulias et al, 1992;Mayer and Shlien, 1987), most investigations do not (Daar et al, 1982(Daar et al, , 1984Ghosh et al, 1986;Momburg et al, 1986;Gutierrez et al, 1987;Degener et al, 1988;Ruiz-Cabello et al, 1988;Norazmi et al, 1989;Bedossa et al, 1990;Horie et al, 1990). The discrepancy may be explained by the selection of normal controls, as slight inflammatory changes are known to induce DR-expression (Rognum et al, 1987).…”