The distribution of SOX2 antibody titres among the SCLC (no PND) patients was almost bimodal (Fig. 2), and statistically different in distribution from both the LEMS-SCLC (P < .0001) and PCD-SCLC (P = .007) patients (Kolmogorov-Smirnov two-sample test). This evidence concerns the gene SOX2 and small cell lung carcinoma.