This study uses single-cell RNA sequencing to map the cellular landscape of the human liver, identifying 20 distinct cell populations, including hepatocytes, endothelial cells, cholangiocytes, hepatic stellate cells, B cells, conventional and non-conventional T cells, NK-like cells, and intrahepatic monocyte/macrophage populations. The authors developed a gentle dissociation protocol to avoid damaging fragile cell types and applied this to fresh liver tissue from five healthy donors. The results provide a comprehensive view of the human liver's cellular composition, highlighting the presence of two distinct populations of intrahepatic macrophages with inflammatory and immunoregulatory functions. The study also describes the zonation of hepatocytes and endothelial cells, and the transcriptional profiles of cholangiocytes, hepatic stellate cells, and intrahepatic immune cells, contributing to a better understanding of the liver's immune microenvironment and its role in liver disease.This study uses single-cell RNA sequencing to map the cellular landscape of the human liver, identifying 20 distinct cell populations, including hepatocytes, endothelial cells, cholangiocytes, hepatic stellate cells, B cells, conventional and non-conventional T cells, NK-like cells, and intrahepatic monocyte/macrophage populations. The authors developed a gentle dissociation protocol to avoid damaging fragile cell types and applied this to fresh liver tissue from five healthy donors. The results provide a comprehensive view of the human liver's cellular composition, highlighting the presence of two distinct populations of intrahepatic macrophages with inflammatory and immunoregulatory functions. The study also describes the zonation of hepatocytes and endothelial cells, and the transcriptional profiles of cholangiocytes, hepatic stellate cells, and intrahepatic immune cells, contributing to a better understanding of the liver's immune microenvironment and its role in liver disease.