The high rate of SOX2 positivity in LEMS and LEMS-PCD may indicate that within SCLC cells, the SOX2 proteins may couple with the intracellular domains of the VGCC complex: although the cellular localisation of SOX2 is thought to be intranuclear, studies in adult stem cells have demonstrated SOX2 proteins principally in the cytoplasm, including possible cell surface distribution (Zuk, 2009). Here, SOX2 is linked to small cell lung carcinoma.