CACNA1B and Lambert-Eaton myasthenic syndrome: While it has historically been difficult to differentiate LEMS from symptomatically related disorders, in 1989 Sher and coworkers showed that antibodies against VGCCs produced in LEMS could immunoprecipitate 125I-ω-conotoxin GVIA-bound N-type VGCCs (Cav2.2), which are elevated in about half of LEMS patients [45,48].