CNTNAP2 and viral encephalitis: However, more recent studies have specified the particular targets as being components of the VGKC – Leucine-rich glioma-inactivated 1 (LGI1) and Contactin Associated Protein-like 2 (CASPR2) [22], such that the value of testing for generic VGKC antibodies, using radioimmunoassay is now questioned in encephalitis [23], and the clinical recommendation is to only test for LGI1 and CASPR2 [24].