Before revision:  i. e., the instability spontaneously appears when the cell density in the sheet plane increases and/or when the number of neighboring cellsdecreases, as observed in vivo. The instability is also facilitated by the delaminated cell-specific force generation upon lateral surfaces, which are driven by cell-intrinsic genetic programs during cell invasion and apoptosis in physiology. In principle, this instability emerges from the force balance on the lateral boundaries among cells. Additionally, taking into account the cell-intrinsic force generation on apical and basal sides , which are also broadly observed in morphogenesis, homeostasis, and carcinogenesis, we found apically/basally directed cell delaminations and pseudostratified structures, which could universally explain mechanical regulations of epithelial geometries in both physiology and pathophysiology{\it   .
After revision:  i. e., the instability spontaneously appears when the cell density in the apical and basal sides , which are also broadly observed in morphogenesis, homeostasis, and carcinogenesis, we found apically/basally directed cell delaminations and pseudostratified structures, which could universally explain mechanical regulations of epithelial geometries in both physiology and pathophysiology{\it .