NCR1 and Chronic colitis: In order to test the role of HIF-1α in NKp46+ gut ILCs in chronic injury in the large intestine, we used mice with a targeted deletion of HIF-1α, via crosses of the loxP-flanked HIF-1α allele to the Ncr1 (NKp46) promoter–driven Cre recombinase, specific to NKp46-expressing ILC1s, including NK cells and ILC3s (Ncr1cre+ HIF-1αfl+/fl+ mice, termed HIF-1α KO) (Eckelhart et al, 2011; Krzywinska et al, 2017) and WT littermates to a scheme of repetitive dextran sodium sulfate (DSS) exposure (Fig 1A), which induces mucosal damage and chronic colitis (Okayasu et al, 1990).