Phosphatidylserine receptor that plays an important functional role in regulatory B-cells homeostasis including generation, expansion and suppressor functions (PubMed:21821911, PubMed:25645598, PubMed:32668241). As P-selectin/SELPLG ligand, plays a specialized role in activated but not naive T-cell trafficking during inflammatory responses (PubMed:24703780). Controls thereby T-cell accumulation in the inflamed central nervous system (CNS) and the induction of autoimmune disease (PubMed:24703780). Regulates also expression of various anti-inflammatory cytokines and co-inhibitory ligands including IL10 (PubMed:25582854, PubMed:25645598). Acts as regulator of T-cell proliferation (PubMed:15793576). May play a role in kidney injury and repair (By similarity). Interacts with STAM (By similarity). Interacts with SELPLG (PubMed:24703780). Expressed by stimulated T-cells. Expressed during primary antigen stimulation (PubMed:11725301). Expressed at higher levels on B rather than T-cells, both constitutively and after activation (PubMed:21821911). Possesses an immunoglobulin V-like domxain, a mucin domain, a single transmembrane region, and a cytoplasmic tail containing a tyrosine phosphorylation motif. Highly polymorphic. Depending on the alleles, expression is associated with an increase and early (BALB/c allele) or decrease (HBA allele) of T-helper type 2 cytokine expression. Associated with asthma susceptibility. Mutant show progressive loss of IL10 production in B-cells and with age develop severe multiorgan tissue inflammation (PubMed:25582854). Mucin-domain deletion mice exhibit decreased phosphatidylserine binding and are also unable to produce IL10 in response to apoptotic cells (PubMed:25645598). Specific deletion on B-cells results in spontaneous systemic autoimmunity (PubMed:32668241). Belongs to the T-cell and airway phenotype regulator (Tapr) locus, a single chromosomal region that confers reduced T-helper type 2 responsiveness and protects against airway hyperactivity (AHR), the hallmark of human asthma. Belongs to the immunoglobulin superfamily. TIM family.