Table 1.

Heterogeneity of skin ILC2.

Cell identity
Cell types	Detection	Characteristics	References
Mouse
ILC2	Flow cytometry	Detected by expression of ST2 and CD25 Detected by expression of IL-7R, ICOS and c-Kit	(5, 46) (7)
IL-13 producing ILC2	Flow cytometry in IL-13 reporter mice		(6)
IL-5 producing ILC2	Single cell and bulk RNAseq in IL-5 reporter mice	High expression of Gata3, Il7r, Crlf2, Icos, Ccr6, Itgae, Il18r1, low expression of Il1rl1	(8)
IL-13 producing ILC2	Flow cytometry in IL-13 reporter mice	High expression of ICOS, low expression of ST2	(10)
Epidermal ILC Dermal ILC	Single cell and bulk RNAseq and flow cytometry	High expression of CCR6, CD103, Rorc, Lta, Il13 (ILC3-like) High expression of ICOS, Gata3	(9)
ST2+ ILC2 in subcutis		High expression of ST2, CD25, Sca-1, KLRG1, Gata3, Il5
Inflammatory ILC2	Single cell RNAseq and flow cytometry	Expression of GATA3, RORγt, CCR6, production of IL-5, IL-13 and IL-17A	(40)
Human
ILC2	Flow cytometry	Detected by expression of ST2 and CD25 Detected by expression of IL-7Ra and CRTH2	(5, 22) (7)
ILC2	Immunohistochemistry	Expression of GATA3, IL-7Ra and CRTH2	(21)
ILC2	Single cell RNAseq	Expression of GATA3 and RORA	(23)
Mixed ILC2 and ILC3		Coexpression of GATA3, RORC, AHR, IL5, IL13, IL22, IL26 (increase in atopic skin)
Cytokine response
Activating cytokines	Mice	Models	References
TSLP	Tslp−/− (C57BL/6)	MC903 atopic-like dermatitis	(5)
IL-33	Il1rl1−/− (BALB/c) Il1rl1−/− hK14mIL33tg (C57BL/6)	MC903 atopic-like dermatitis Wound healing IL-33 overexpression in keratinocytes	(7) (46) (26)
IL-25	Il17rb−/− (BALB/c)	MC903 atopic-like dermatitis	(7)
	K14-Cre Il25flox/flox (C57BL/6) Rora-Cre Il17rbflox/flox (BALB/c)	OVA allergic skin inflammation	(27)
IL-18	Il18−/− (C57BL/6) KIL-18Tg (C57BL/6)	MC903 atopic-like dermatitis IL-18 overexpression in keratinocytes	(8) (28)