Non-professional phagocytes
The elimination of damaged or dying cells is very important to protect the surrounding cells or the organism from damage. Phagocytosis is a mechanism to eliminate such cells. A less known phenomenon is phagocytosis by non-professional phagocytes. These are cells that do not belong to the inflammatory cells but can still phagocytise. These events have sometimes been described in tumours. In 2007 M. Overholtzer described in a groundbreaking paper the penetration of cells into other cells with a subsequential elimination of the cells and called the mechanism Entosis (1). We could describe the reverse mechanism, that necrotic cells are phagocytized by living cells and then eliminated (2). We use the neutral term of the cell-in-cell (CIC) phenomenon. We have shown that CIC has an important prognostic significance that may be more significant than apoptosis (3).