WE have described two polymorphic variants of serum albumin (Fig. 1). Of these, albumin Naskapi the electrophoretic mobility of which is greater than that of the usual albumin (albumin A) is relatively common in several North American Indian tribes. It has been identified in sera from Indians of the Naskapi, Montagnais, Sioux, Northern Athabascan and Chippewa tribes1–3. Fast moving electrophoretic variants found in the Forest Cree4 and the Ojibwa and Blackfoot Indians5 may also be albumin Naskapi, although direct comparisons have not been made.