<unk> is the shrinking or return of an organ to a former size. At a cellular level,<unk> is characterized by the process of proteolysis of the basement membrane (basal lamina), leading to epithelial regression and apoptosis, with accompanying stromal fibrosis. The consequent reduction in cell number and reorganization of stromal tissue leads to the reduction in the size of the organ.
Involution 
Sex selection
Functional integration 
Penetrance
Aplasia
Subinvolution
Cordance
Dominance 