ULBP1 and hepatocellular carcinoma: MICA/B and ULBP4 were moderately (IHC score: 4–6) or highly (IHC score: 7–12) expressed in more than 2/3 HCC tumor samples, whereas ULBP1, ULBP3, and UBP2/5/6 were not (IHC score: 0) or lowly (IHC score: 1–3) expressed in more than 2/3 HCC tumor samples (Figure 2A).