TBR1 and steatosis: In contrast, staining results for the rats in the model group and in the AAV-TβR1 4W group indicated the occurrence of varying degrees of hepatic fibrosis, which was characterized by a significant increase in collagen fibers; substantial fibrous hyperplasia in the portal region accompanied by inflammatory cell infiltration; broad fibrous septa extending deep into the liver tissue and resulting in the formation of pseudolobules of varying sizes; and the occurrence of steatosis in a portion of the liver cells.