Type i hypersensitivity reaction 2

What is the significance of IL-4 in the context of type I hypersensitivity reactions?

1: IL-4 causes class switching of B cells to produce IgE
2: IL-4 recruits mast cells and basophils to the site of allergen
3: IL-4 induces degranulation of eosinophils
4: IL-4 suppresses the immune response to prevent hypersensitivity