Table 1.

CXCR4 and CXCL12 protein cysteine counts for selected vertebrates

Species	CXCR4 Cysteines	CXCL12 Cysteines
Pm	15	–
Le	12	7
Cm	11	6
Sc	9	6
Tr A	11	4
Tr B	12	10
Dr A	12	4
Dr B	11	4
Lc	9	5
Gg	9	4
Mm	9	5
Hs	9	5

CXCL12, C-X-C motif chemokine ligand 12; CXCR4, chemokine receptor type 4. Cm, elephant shark (Callorhincus milii); Dr, zebrafish (Danio rerio); Gg, chicken (Gallus gallus); Hs, human (Homo sapiens); Mm, mouse (Mus musculus); Lc, coelacanth (Latimeria chalumnae); Le, little skate (Leucoraja erinacea); Pm, lamprey (Petromyzon marinus); Sc, catshark (Scyliorhinus canicula); Tr, pufferfish (Takifugu rubripes).