As illustrated in Table 2, a serum gamma-glutamyl transpeptidase level cutoff value of 283.89 or higher exhibited a diagnostic sensitivity of 90%, specificity of 78.43%, positive predictive value (PPV) of 76.60%, negative predictive value (NPV) of 86.27%, and accuracy of 83.52% for diagnosing BA (see Table 3). The gene discussed is GGTLC1; the disease is breast angiosarcoma.