We have previously identified a second cerebellar degeneration antigen, ß-NAP, is expressed in neuroectodermal tumor cell lines, and encodes a neuron-specific vesicle coat protein. We are currently pursuing studies to define the role of ß-NAP in neuron-specific vesicle transport (Newman LS, McKeever MO, Okano HJ and Darnell RB. Cell, 82:773-783, 1995.). More recently, we have identified a small cell lung cancer antigen termed Sox21 (Ohba H, Chiyoda T, Endo E, Yano M, Hayakawa Y, Sakaguchi M, Darnell RB, Okano HJ, Okano H. Neurosci Lett. 358:157-6, 2004). We are actively interested in identifying new onconeural antigens. As we believe that there are a significant number of onconeural antigens that have not yet been identified, we encourage clinicians to contact us if they may have a patient with a paraneoplastic neurologic disorder, even if those patients have tested negative to all known PND antigens. We continue to study the biology of the PNDs associated with the Nova and Hu antigens.