Identification of master regulators like BCL6, TP53, KTLG offers a mechanistic model linking chronic systemic activation of mast cells and eosinophils to the development and aggravation of multi-system conditions such as ME/CFS (30, 160, 196, 202, 280–282). The gene discussed is BCL6; the disease is myalgic encephalomeyelitis/chronic fatigue syndrome.