SOX2 and breast cancer: In patients without neurological symptoms, SOX2 antibodies were found in 77/259 (29.7%) patients with SCLC, but in only 15/238 (6%) of non-SCLC, 0/75 (0%) of breast cancer, 4/104 (4%) of ovarian cancer, and 8/414 (1.9%) of age matched healthy controls (Fig. 1, Table 1).