Additionally, PCR analysis revealed that the profibrotic response was significantly enhanced following TAC operation, corroborated by the upregulation of several fibrosis-associated genes, including connective tissue growth factor (CTGF), Collagen 1 (Col1a1) and Collagen 3 (Col3a1) (Figures 3C–E). This evidence concerns the gene COL1A1 and persistent truncus arteriosus.