CXCR4 and fibrosis: SDF‐1, acting via CXCR4, recruits circulating monocytes, fibrocytes, and other cells to the injured lung and their transformation into myofibroblasts, the effector cells in fibrosis.2 Over the past decade, small molecule CXCR4 inhibitors or antagonists were developed, including AMD3100 (Plerixafor), CTCE‐9908, and AMD 070.