Methods of inhibiting activation of a mast cell and/or treating a disease induced by activation of a mast cell in a subject are provided. Accordingly there is provided a method comprising contacting a cancerous mast cell with an effective amount of a multivalent agent which binds and activates Siglec-7, thereby inhibiting activation of the cancerous mast cell. Also provided is a method comprising contacting a mast cell with an effective amount of an agent comprising: a first moiety which binds and activates Siglec-7 and a second moiety which binds activates a mast cell activating receptor, thereby inhibiting activation of the mast cell. Also provided are agents and compositions for and methods of inhibiting activation of a mast cell and/or treating a disease induced by activation of a mast cell in a subject.
