Table 2. Expression and protein localization of Oat1, Oat3, Oct1, and Hnf4α in the proximal tubule.

Gene	Expression in PT	Protein localized to PT	Renal function through knockout
Oat1	Microarray [13]	IHC [53]	[5]
	Microarray, ISH [20]	IHC [52]
Oat3	Microarray [13]	IHC [53]	[9]
		IHC [52]
Oct1	Microarray [20]	IHC [54]	[57]
	mRNA expression (Whole kidney) [55]
	ISH [54]
Hnf4α	Microarray [20]	IHC [56]
	ISH [56]

Evidence from existing literature validates the result of microarray analysis. The genes and protein products of Hnf4α, Oat1, Oat3, and Oct1 are present in the proximal tubule during organogenesis and adulthood.