Fig 1: (A) H&E stain of biopsy tissue showing HCC with a prominent lymphocytic infiltrate. Scale bar is 200 µm. (B) IHC staining of biopsy tissue confirmed that the infiltrating lymphocytes were predominantly CD8+ (Leica [4B11]). Scale bars are 200 µm and 20 µm (inset). (C and D) There were also rare CD56+ (Leica [PA0191]) cells present in the biopsy specimen. Scale bars are (C) 200 µm and (D) 50 µm. (E and F) CD8 IHC staining of the resected liver segment showed a residual brisk CD8+ immune cell infiltrate into a 4-mm scar and no residual cancer cells. Asterisks denote the presumed border of the original tumor. Scale bars are (E) 2 mm and (F) 100 µm. HCC, hepatocellular carcinoma; H&E, hematoxylin and eosin; IHC, immunohistochemistry.