regionalization dorsal/ventral pattern formation biological_process The regionalization process in which the areas along the dorsal/ventral axis are established that will lead to differences in cell differentiation. The dorsal/ventral axis is defined by a line that runs orthogonal to both the anterior/posterior and left/right axes. The dorsal end is defined by the upper or back side of an organism. The ventral end is defined by the lower or front side of an organism. dorsoventral pattern formation dorsal/ventral pattern specification dorsal-ventral pattern formation GO:0009953