Although there are many questions such as accuracy of diagnosis and small percentage of ROP patients harboring mutations in FEVR genes that need to be addressed before any conclusion can be drawn, based on the studies conducted from around the world involving different ethnic background patients, it is possible that the advanced ROP could be in fact a sporadic FEVR and the prematurity is an environmental factor that simply speeds up the progression of the disease. Here, FZD4 is linked to retinopathy of prematurity.