Table 1.

Cl transporters

Family	Gene	Alias	Distribution	Ions	Cl− Influx(I) or efflux(E)	References
Slc4a anion exchangers	Slc4a1	kAE1	kidney	Cl−/HCO3−	I
	Slc4a1	eAE1	erythrocyte	Cl−/HCO3−	I	Alper et al. 2002;
	Slc4a2	AE2	widespread	Cl−/HCO3−	I	Romero et al. 2004
	Slc4a3	AE3	brain, heart	Cl−/HCO3−	I
	Slc4a9	AE4	kidney, stomach	Cl−/HCO3−	I	Tsuganezawa et al. 2001;Ko et al. 2002;Xu et al. 2003
Slc4a10	NCBE	brain, ileum, kidney	Cl−/Na++ 2HCO3−	E	Wang et al. 2000
Slc12a electro neutral, cation– coupled cotransporter	Slc12a1	NKCC2	kidney	Na++ K++ 2Cl−	I
	Slc12a2	NKCC1	widespread	Na++ K++ 2Cl−	I
	Slc12a3	NCC	kidney	Na++ Cl−	I	Payne et al. 2003
	Slc12a4	KCC1	widespread	K++ Cl−	E
	Slc12a5	KCC2	neuron-specific (brain)	K++ Cl−	E, I	Payne et al. 2003;
	Slc12a6	KCC3	widespread	K++ Cl−	E
	Slc12a7	KCC4	widespread	K++ Cl−	E	Gamba, 2005
	Slc12a8	CCC9	widespread	?	?	Hebert et al. 2004;Gamba, 2005
Slc12a9	CIP1	widespread	?	?	Gamba, 2005
Slc26a	Slc26a3	DRA	colon, pancreas, trachea	Cl−/HCO3−	I	Greeley et al. 2001;Sterling & Casey, 2002;Mount & Romero, 2004
	Slc26a4	pendrin	thyroid, inner ear, kidney	Cl−/HCO3−	I	Sterling & Casey, 2002;Mount & Romero, 2004
	Slc26a6	PAT1	pancreas, kidney, stomach	Cl−/HCO3−	I	Sterling & Casey, 2002;Wang et al. 2002;Mount & Romero, 2004
	Slc26a7	SUT2	kidney, stomach	Cl−/HCO3−	I	Sterling & Casey, 2002;Petrovic et al. 2003, 2004
	Slc26a8	TAT1	testis	Cl−	?	Lohi et al. 2002;Sterling & Casey, 2002
	Slc26a9		lung, stomach	Cl−/HCO3−	I	Sterling & Casey, 2002;Xu et al. 2005
	Slc26a11		widespread	Cl−/HCO3−	?	Vincourt et al. 2003;Soleimani & Xu, 2006

The genes are classified by sequence homology into three families: Slc4a, Slc12a and Slc26a. Several of the transporters have common names, some of which are listed in the ‘Alias’ column. The ‘Distribution’ and ‘Ions’ columns are not exhaustive. Ions separated by ‘+’ are cotransported; ions separated by ‘/’ are exchanged. The ‘Cl⁻ influx (I) or efflux (E)’ column indicates the likely direction of Cl⁻ transport in vivo in the tissues that have been studied.