TPP1 and granular corneal dystrophy type II: The well-characterized telomere-protecting protein complex, i.e., the telomere shelterin complex, comprises six essential proteins: telomeric repeat binding factor 1 (TERF1, also referred to as TRF1); telomeric repeat binding factor 2 (TERF2, also called TRF2); TERF1 interacting nuclear factor 2 (TINF2, commonly known as TIN2); TERF2 interacting protein (TERF2IP, known as RAP1); adrenocortical dysplasia (ACD, with TPP1 being another commonly used name for ACD); and the protection of telomeres 1 (POT1) [2,3,4].