Figure 3. A previously described C > T polymorphism in the MMTV DNA sequence. In four of the MMTV positive cases, sequencing of both the ENV1 and ENV2 amplicons was accomplished. One of the ENV1 cases showed a previously described C > T polymorphism, that did not cause an amino acid substitution. The wild type sequence was named ENV1-C, whereas the polymorphic sequence was named ENV1-T. A: ENV1-C positive case from Luni, Liguria. B: The ENV1-T polymorphic case from Alghero, Sardinia.