Protein dopey-2 (DOPEY2), also called C21ORF5, is a member of Dopey family involved in morphogenesis. It is expressed in all human tissues, namely brain, spinal cord, liver, pancreas, kidney, spleen, heart, lung, skeletal muscle, testis, ovary, fetal brain, and fetal liver. It have demonstrated to be overexpressed in Down syndrome tissues, as a candidate gene for trisomy 21.