PKD1 and cyst: A possible scenario is that the upregulation of some cytokines in Pkd1 mutant collecting duct cells in cystic kidneys during cyst initiation and progression leads to increases in the secretion of those cytokines, and these secreted cytokines may then bind to their receptors on neighboring cells, including macrophages, T cells and fibroblasts, to affect the biology and function of those cells, including the expression of cytokines and cytokine receptors as well as epigenetic regulators in these recipient cells.