SLC22A1 and hepatocellular carcinoma: Moreover, specific antibodies were used to detect SLC22A1, SLC22A2 and SLC22A3 protein by immunofluoresence confocal laser scanning microscopy in HCC tumor tissue (n = 7 from HCC cohort 1; Tables S1 and S3 in Additional file 1) and histologically normal liver tissue (n = 5 from IKP-liverbank; Tables S1 and S4 in Additional file 1) derived from patients without HCC.