Putative neuronal cell surface protein involved in cell-cell-interactions. Homodimer. Interacts with NRXN1 in a calcium-dependent manner. Interacts through its C-terminus with DLG4/PSD-95 third PDZ domain. Expressed at highest levels in heart. Expressed at lower levels in liver, skeletal muscle and pancreas and at very low levels in brain. Disease susceptibility is associated with variants affecting the gene represented in this entry. Disease susceptibility is associated with variants affecting the gene represented in this entry. Belongs to the type-B carboxylesterase/lipase family. Extended N-terminus.