SOX2 and small cell lung carcinoma: The positivity rate for individual AAb assays in the new seven-AAb panel ranged in NSCLC from 1 (for SOX2) to 14 % (for MAGE A4) and in SCLC from 8 (for MAGE A4 and GBU4-5) to 17 % (for SOX2 and p53), with specificity for each antigen being ≥96 % (Table 1).