First of all, the PKZIP trojan horse is very real. We had a bout of it here when it came in attached to a downloaded IBM file. It is not a hoax. As for the evidence regarding the immunological benefits of nucleotide-containing infant formulas, I saw the data presented by Ross Labs at the recent Experimental Biology conference, and I have to say the evidence is pretty weak. The nucleotide-containing formula boosted antibody responses to all the vaccines they tested, but they didn't know what isotype the antibodies were (a sign of effectiveness). It also concerns me when some dietary factor shifts the immune system into high gear so non-specifically. What about autoantibodies? What about long-term immune system development? As we can tell from formula-based infant weight gain curves and charts, "more is not necessarily better". ----------- J. Paul Zimmer Developmental and Clinical Immunology University of Alabama at Birmingham