LAP3 and asthma: Also, the S1P regulates various molecular functions that are essential for the pathogenesis of asthma and respiratory diseases such as the bioactive lipid receptor activity, S1P receptor activity, G protein-coupled receptor activity, signaling receptor activity, transmembrane signaling receptor activity, molecular transducer activity, endopeptidase activity, peptidase activity acting on L-amino acid peptides, peptidase activity, and serine-type peptidase activity.