“…Thus, despite lack of direct proof, the hypothesis of dilution of copper into an expanded body pool of the metal has generally been accepted, presumably because it is inherently reasonable. There is, however, an alternative method of studying the problem; patients with primary biliary cirrhosis have concentrations ofcopper in their livers comparable with those found in the livers of patients with Wilson's disease (Gubler, Brown, Markowitz, Cartwright & Wintrobe, 1957;Hunt, Parr, Taylor & Trott, 1963;Sass Kortsak, 1965;Leeson & Fourman, 1967;Smallwood, Williams, Rosenoer & Sherlock, 1968;Worwood, Taylor & Hunt, 1968). Thus a study of the handling of radioactive copper by patients with primary biliary cirrhosis should help to clarify the role of an expanded liver pool of copper on the rate of radioactive copper incorporation into caeruloplasmin.…”