The allotypes described in Figure 4, G1m(1,17), G1m(3) and the "null mutant", along with the the aglycosyl mutants of the G1m(1,17) and G1m(3) were expressed along with the CAMPATH-1 (CDw52) fully reshaped variable regions [18] , [48] and were then compared for their abilities to lyse human lymphocytes with autologous complement. The results are given relative to the "wild-type" IgG1 G1m(1,17). (Data M.R. Clark unpublished).