Al worked with Jerry at the NIH and while the lab wrote a program to search the then newly accumulating DNA sequence data base to look for genomic repeats as evidence of gene mobility. Using this approach Al was the first to define large scale genetic repeats in the mammalian genome (Science 1983). He is now head of the Laboratory of Chemical Carcinogenesis at the NIH in Bethesda. Al can be reached at: af6z@nih.gov.