A conjugate comprising interleukin-4 (IL4) and a specific binding member is disclosed. The specific binding member preferably binds an extra-cellular matrix component associated with neoplastic growth and/or angiogenesis, and the conjugate may be used for targeting IL4 to tissues in vivo. In particular, the therapeutic use of such conjugates in the treatment of a disease/disorder, such as cancer and/or autoimmune diseases, including rheumatoid arthritis (RA), multiple sclerosis (MS), endometriosis, inflammatory bowel disease (IBD), psoriasis, psoriatic arthritis, and periodontitis is envisaged. Other diseases which may be treated or prevented using the conjugates include autoimmune insulitis and diabetes, in particular autoimmune diabetes. In the treatment of cancer, the conjugate may be administered in combination with a conjugate comprising either interleukin-12 (IL12) or interleukin-2 (IL2) and a specific binding member. In the treatment of autoimmune diseases, the conjugate may be administered in combination with a glucocorticoid, such as dexamethasone.