Cell individuality: a basic multicellular phenomenon and its role in the pathogenesis of disease

Every type of cell has its own special features that differentiate its members qualitatively from cells of other types. Within the same type of cells, however, every single cell also has its own unique characteristics that deviate itself from other individual cells, although they are alike collectively. These kinds of individual differences between cells are described here as cell individuality, which says basically that, within a cell population or even within a multicellular organism, every cell is a unique individual living being; and no single cell could be completely identical to another, regardless of how similar to each other they are. The individuality of a single cell can be represented by all sorts of cell characteristics, which are countless and range from physiological activities to molecular constituents. These individual differences in cell characteristics are generally presented much more in degree or in quantity, rather than in kind or in quality. Moreover, such cell individuality or quantitative variations within or even between cell populations may also play a basic role in the pathogenesis of disease, and particularly in the susceptibility of cells to the disease process.