A 15-member three-generation family of Eastern Mediterranean descent was previously studied, and an association between CYP1A1 (cytochrome P1450, benzo[a]pyrene hydroxylase) inducibility and aCYP1A13‘-polymorphism (theMspI 1.9 kb allele) was reported (Petersenet al. Am J Hum Genet1991: 48, 720–725). Here we have re-examined the original DNA (and in some cases, newly prepared DNA from freshly drawn blood) from these same individuals, in order to assess the association between CYP1A1 inducibility and both theCYP1A1geneMspI RFLP polymorphism and theCYP1A1gene A→G polymorphism at codon 462. This latter nucleotide change results in an altered amino acid (462Ile →Val), which is purported to increase CYP1A1 enzyme activity and mutagenicity towards benzo[a]pyrene about two-fold among Japanese. Among the 15 members of this three-generation family examined, no absolute correlation was observed between the 1462V genotype and either the Msp I 1.9kb allele or the CYP1A1 inducibility phenotype. We also found no absolute correlation between theMspI 1.9 kb allele and the CYP1A1 inducibility phenotype.