Figure 1.

Cysteine disulfide bonds in different classes of chemokines. In CC chemokines, the first two conserved cysteines are adjacent. The first and the third, and the second and the forth conserved cysteines form disulfide binds. In CXC chemokines, the first two conserved cysteines are separated by one amino acid. In the CX3C chemokine, three amino acids separate the first two conserved cysteines. There are only two conserved cysteines in the XC class of chemokines. The name and number of human members in each class of chemokines are on the right.