RB1 and retinoblastoma: Expression patterns and quantitative and semiquantitative analysis of the markers p19, Ki-67, MSX1, MSX2, PDL1, pRB, and CYCLINA2 were performed on tissue sections from week 8 of human eye development, retinoblastoma, normal human eye, and ocular melanomas using hematoxylin and eosin (Figure 1) and immunofluorescence staining and quantitative analysis (Figure 2, Figure 3, Figure 4, Figure 5 and Figure 6).