Multiple sequence alignment of lymphotactin (XCL1) and interleukin-8 (IL-8). The corresponding sequences were labeled with their GenBank entries (denoted by the GenBank identifier - gi) and organism of origin. The numbers in brackets refer to the positions of the presented sequence fragments. The observed (Protein Data Bank entries 1J8I_A for XCL1 and 1IL8_A for IL-8) and predicted (Psipred) secondary structure elements are coded with letters (H - a-helix, G - 310 helix, E - b-strands). Disulphide bridges in IL-8 has been marked with arrows and numbered.