Receptors that mediate this process trigger both a fast, excitatory signal and a slow, inhibitory signal according to the LEGI model. Receptors that facilitate this process (-5[1])are divided into three families based on whether there are 0, 1, or 3 amino acids between their (15[1])two N-terminal cysteines. Pro-inflammatory formyl peptides like fMLF mediate pattern recognition and this process. (-5[1])Leu·ko·tri·ene B4, complement (15[1])protein 5a, and inter·leu·kin 8 are the main mediators of this (-5[1])process in neutrophils. HIV (*) enters T-cells and macrophages by hijacking (10[1])two co-receptors that mediate this (10[1])process, (-5[1])called (10[1])CCR5 and CXCR4. Many immune cells use (10[1])a gradient-sensing form of this (10[1])process (10[1]-5[1])to target (10[1])sites of foreign invasion. For (10[1])10 points, name this process in which (10[1])a cell (10[1])moves in (10[1])response (10[2])to (10[1]0[1])a chemical stimulus. (10[1])■END■ (10[4]0[6])