Given that sorafenib has an sEH-inhibitory effect in addition to its tyrosine kinase inhibitory action [8,9,13] and has also been described as a CYP inhibitor [12], the aim of this small pilot study was to assess epoxy lipid metabolites in peripheral blood of HCC patients with and without sorafenib therapy in order to assess whether sorafenib treatment might increase the presence of potentially tumor growth-promoting EETs, as well as of potentially tumor growth-suppressing omega-3 derived EDPs in HCC patients in a routine treatment setting. The gene discussed is EPHX2; the disease is neoplasm.