Antigen-presenting protein that binds self and non-self lipid and glycolipid antigens and presents them to T-cell receptors on natural killer T-cells. {ECO:0000269|PubMed:10786796, ECO:0000269|PubMed:10890914, ECO:0000269|PubMed:10899914, ECO:0000269|PubMed:21167756}. This is the function of ENSG00000158481 (CD1C, CD1c molecule).