Hypothetical scheme of intracellular signaling pathways involved in human neutrophil activation in response to angiotensin II. Binding of Ang II to AT1 receptors in human neutrophils would initiate a complex cascade of signaling pathways leading to the activation of NADPH oxidase, with the concomitant production of ROS and of kinases p38, ERK1/2, and JNK1/2 of the MAPK family. The increase in cytosolic Ca²⁺ resulting from AT1 receptor activation would in turn stimulate CaN activity, promoting nuclear translocation of NF-κB. This transcription factor would activate the expression of a number of genes involved in neutrophil cell activation, including CaN subunits encoding genes.