CD4 and autoimmune hepatitis: During AIH, trogocytosis can occur between MHC class II-expressing HCs and CD4+ T cells in a TCR dependent manner resulting in peptide-MHC class II transfer onto CD4+ T cells and dying HCs that lose part of the hepatocyte membrane (55, 56) (Figure 3A). This process named piecemeal necrosis is characterized by necrosis of periportal HCs with inflammation extending from the portal tract into the periportal zone (57).