FGF19 and breast cancer: Metastatic cancer cells can induce neutrophils to form metastasis‐supporting NETs in target organs, with liver metastases exhibiting the most abundant NETosis, which might mediate the hepatotropism of metastatic cancer cells, such as CRC and breast cancer cells.[18, 40] To investigate whether FGF19 promotes NETosis in liver metastatic niches and determine its underlying mechanism, we first examined the induction of NETosis by FGF19 in vitro.