Importantly, activation of inflammation was also implicated in shaping of the metastatic microenvironment (Coffelt et al., 2015; Quail et al., 2017; Albrengues et al., 2018), but the role of fibroblasts in mediating inflammation at the metastatic site is only recently emerging: recent studies implicated CAF-derived cytokines including IL-1β, IL-33, and CXCL9/10 in promoting breast cancer lung metastasis (Pein et al., 2020; Ershaid et al., 2019; Shani et al., 2020). The gene discussed is IL33; the disease is breast cancer.