Considering the crucial roles of TGF-β2/activin receptor-like kinase 5 (ALK5)/SMAD2/3 signaling in neovascularization, unraveling the molecular mechanisms of HTRA1 upregulation involving the in/del sequence is important in understanding the development of CNV in AMD. Here, TGFBR1 is linked to age-related macular degeneration.