CCL4 and pulmonary fibrosis: Notably, cytokines associated with pulmonary fibrosis (i.e. TIMP-1, GM-CSF) (Isabelle et al. 2012; Zelko et al. 2016), profibrotic chemokines (i.e. MCP-1, MIP-1α, MIP-1β, TARC, MDC, KC), and anti-fibrotic chemokines (i.e. MIG, IP-10) were upregulated by cSiO2 exposure at both timepoints (Figure 5).