Lc-11 (Hunt B, Jones) as a mutually exclusive specificity to Lc-1,2, and 3 in the main human leukocyte group.

Summary. The specificity Lc-11, defined by properly adsorbed Hunt serum (Hunt B), or by the monospecific serum Jones, reveals a completely mutually exclusive relationship to Lc-1, 2, and 3 of the main (HL-A) leukocyte group, when tested against 290 random Caucasian donors and 56 negro donors. Jones antiserum was produced by planned immunization directed towards producing a specificity of this nature. A structural relationship of the various human leukocyte factors is proposed which is strictly analogous to the Rh system in man or the B blood group system in cattle. A number of criteria are set forth, the fulfillment of which would reinforce this interpretation.