Entosis is a process that stimulates cell-in-cell formation. During entosis, a cell integrates itself in an adjacent host cell, and then initiates its cellular death within the phagosome. The entosis engulfment mechanism involves epithelial adherens junctions. These adherens junctions are composed of the receptor E-cadherin and protein alpha-catenin. Entotic cells also have an active role in controlling their uptake through RhoA-GTPase activity and RhoA effector kinases Rho-kinases I and II. Entosis depends on the actomyosin contractility regulated by the Rho-GTPase activity in the invading cell. Once cell-cell adhesion has begun, the host cell initiates invagination, which is a process that extends its plasma membrane to surround and enclose the target cell. After the target cell is engulfed by the host cell, the entotic vacuole is formed within the host cell. This contains the enclosed target cell and is separated from the host cell's cytoplasm by a membrane. Following this, the host cell proceeds to degrade the target cell using lysosomes.