Inability to attribute susceptibility to primary sclerosing cholangitis to specific amino acid positions of the HLA-DRw52a allele. - Olerup, O; Broome, U; Einarsson, K; Zetterquist, H; Mehal, W; Wordsworth, B; Taylor, C; Bell, J; Fleming, K; Chapman, R; Min, S; Terasaki, P (1991)