FABP4 and hepatocellular carcinoma: Yu et al. (2000) also showed that FABP4 expression was downregulated in the cell line BEL-7404 hepatoma compared to the immortalized normal L-02 hepatic cell line. A theory has been proposed to explain the inconsistency between these reports. FABP4 may play a context-dependent role in hepatic tumor progression (McKillop et al., 2019). Upregulated hepatic or adipocyte-derived FABP4, which is recognized as exogenous FABP4, can enhance HCC progression, whereas tumor-derived endogenous FABP4 suppresses tumor progression (McKillop et al., 2019).