T cells with mixed Th1 and Th17 profiles that express CXCR3 and are recruited to the lungs by CXCL9 and CXCL10. IL-9 possibly induces its own transcription factor PU.1 and thus act in an autocrine and paracrine manner (along with TGFβ) to drive proliferation and survival of ILC2 and γδ T cells. Additional positive loops might be fed by IFNγ, which triggers production of CXCL9 and CXCL10 by macrophages. In severe forms of COVID-19, IL-33, along with IL-2 and IL-7 released by dendritic cells, might further stimulate T-cell expansion t