Upon bacterial lipopolysaccharide stimulation, mediates clathrin-dependent internalization of TLR4 in dendritic cells, resulting in activation of TICAM1-mediated signaling and subsequent IFNB1 production (PubMed:27022195). May regulate B-cell antigen receptor-mediated signaling. Expressed in B-cells, heart, brain, spleen, large intestine and lung (PubMed:19414744). Expressed in dendritic cells and macrophages (PubMed:27022195). Double RFTN1 and RFTN2 mutant mice show no visible phenotype under pathogen-free conditions but show greatly reduced interferon beta production in splenic dendritic cells under poly(I:C) or lipopolysaccharide stimulation. Belongs to the raftlin family.