GFAP and Gliosis: Gliosis, characterized by the upregulation of GFAP, is a well-studied phenomenon in many different RP experimental models, including the rd1 mouse model [52], the rhodopsin knockout mouse model [53], the rd10 mouse model [19,47], the N-methyl-N-nitrosourea (MNU)-induced model [54], the Royal College of Surgeons (RCS) rats [55], and the rds mouse model [56].