Table 5. Immunohistochemical analysis of PD-L1 expression on dog tumor tissues.

Pathology		Positive case/Tested samples (% positive)
Melanoma	Oral cavity	8/8	(100%)
	Skin	1/3	(33.3%)
	Eye	0/2	(0%)
	All	9/13	(69.2%)
Mastocytoma		4/6	(66.7%)
Renal cell carcinoma		7/10	(70.0%)

Immunohistochemical analysis of dog PD-L1 was conducted using dog tumor tissues surgically excised from clinical cases by anti-PD-L1 mAb 5A2-A1. Melanoma cases were divided into 3 groups dependent on the tumor site (Oral cavity, Skin, Eye).