(b).

Species	Cells and tissues reported to express TLR2	Methoda	Information on the level of expression	Reference
Bovine	Monocytes	RT-PCR/FC	Strong	[23, 28]
	Monocyte derived-macrophages	RT-PCR/FC
	Alveolar macrophages	RT-PCR/FC	Intermediate
	Monocyte derived-DCs	RT-PCR/FC	Weak
	CD172+ DCs	RT-PCR/FC
	CD172− DCs	RT-PCR/FC
	CD21+ B cells	RT-PCR	No signal	[28]
Ovine	CD14+ monocytes from PBMCs	FC		[23]
Nilgai and Buffalo	PBMCs, monocytes, DCs, testes, skin	RT-PCR	Higher in Nilgai than Buffalo	[29]
Buffalo	Kidney, endometrium, bone marrow, trachea	RT-PCR	Higher in endometrium and bone marrow
Swine	Mesenteric lymph nodes and Peyer's patches	RT-PCR, IHC, FC	Higher than in spleen by RT-PCR	[30]
	Heart, thymus, lung, kidney, skeletal muscle, small intestine	RT-PCR	Lower than in spleen
	M cells	IHC, FC
	T and B cells	FC	Higher in T cells than in B cells
	Monocytes, macrophage, and granulocytes, but not on peripheral blood lymphocytes	FC		[24]
	Epithelial cells lining body entries (Lung, jejunum, kidney, liver)	IHC
	Alveolar Macrophages	WB		[17]
Equine	PBMCs	RT-PCR		[33]
	Alveolar macrophages	RT-PCR		[31]
	Respiratory epithelial tissues	RT-PCR		[32]
Chicken	Heart, liver, gizzard, muscle	RT-PCR, WB	Strong	[26]
	Spleen, caecal tonsil, bursa, liver	RT-PCR	Strong	[34]
	Heterophils, monocytes, macrophages, B and T cells	RT-PCR		[34, 35]
Canine	Blood mononuclear cells, lymph node, lung, liver, spleen, bladder, pancreas, small intestine, large intestine, and skin	RT-PCR		[18]
	Blood neutrophils	RT-PCR		[27]
	Blood neutrophils, monocytes	FC	Higher levels
	Lymphocytes	FC	Lower levels
Feline	Spleen, thymus	RT-PCR		[36]
	CD4+ T cells, CD8+ T cells, CD21+ B cells	RT-PCR	Higher in B cells than in T cells
	BM-DCs	RT-PCR		[37]
	Palatoglossal mucosa	RT-PCR		[38]

^aRT-PCR: reverse transcription-PCR; FC: flow cytometry; IHC: immunohistochemistry; WB: Western blot.