Plays a suppressive role in osteosarcoma malignancy by inhibiting NF-kappa-B activity (PubMed:27886186). Expressed in the lung and bone. Expressed at lower levels in osteosarcoma tissues (at protein level). The first exon of TMIGD3 isoform 1 (i1) is shared with the first exon of ADORA3 isoform 2 (A3AR i2, commonly known as A3AR), resulting in a fusion protein. Truncated N-terminus. Truncated N-terminus.