Figure 1.

Dead cells act as sentinels of local environmental change. (A) As depicted, the nature of the response of nearby viable cells to dead target cells is determined by three dichotomies: (1) the form of target cell death (apo vs. nec); (2) the dependence of viable cell signals on receptor-mediated recognition vs. engulfment of the dead targets; and (3) the nature of the responding cell (migratory vs. fixed). (B) The responses of MΦ, a migratory cell, are contrasted with those of fixed and organ-specific kidney epithelial cells.