The cognate TAA-AAbs reactivity against the antigen CTAG1B/NY-ESO-1, whose mRNA was most frequently expressed in MTC tissues (15/23 tumors, 65%), was also analyzed and revealed the presence of CTAG1B-AAbs in 15/42 of MTC patients (DSn 36%) but not in a single healthy control, thus yielding DSp values of 100% in the discrimination of MTC patients from the cancer-free individuals (Figure 2). The gene discussed is CTAG1B; the disease is cancer.