Homeobox gene Nkx6.1 lies downstream of Nkx2.2 in the major pathway of β-cell formation in the pancreas. - Sander,M.; Sussel,L.; Conners,J.; Scheel,D.; Kalamaras,J.; Dela Cruz,F.; Schwitzgebel,V.; Hayes-Jordan,A.; German,M. (Development, 2000)