AbstractInterleukin‐4 is a member of the cytokine family, a group of related messenger proteins which collectively help to moderate and control the immune response. It is believed that the folding topology of the β‐sheets of the interleukin‐4 receptor (IL4R) is the same as that seen in the crystal structure of CD4. Although the sequence identity is low, homology modeling techniques have been used to model the IL4R structure from CD4. Refinement by molecular dynamics leads to a suggested structure which has been docked to interleukin‐4 (IL4). Several residues of apparent importance for binding are identified. © 1993 Wiley‐Liss, Inc.