Fig. 1
From: Macrophages: friend or foe in idiopathic pulmonary fibrosis?
Schematic diagram of macrophage subtypes. The M1 subtype is generally considered to be proinflammatory. The M2a subtype is induced by IL-4 and IL-13, which are critical mediators of allergic inflammation. The M2b and M2c subtypes predominately participate in tissue remodeling and fibrosis. BV, blood vessel; M0, monocyte; LPS, lipopolysaccharide; IL, interleukin