Finally, the FGF/FGFR1/NOTCH1 within RB1 variant group has a remarkably high ratio of inner‐tumor CD8+ T cell infiltration, non‐exhausted T cells, exhausted TCD8+PD‐1+LAG3− cells, and TRMCD8+CD69+CD103+cells. This evidence concerns the gene LAG3 and hereditary retinoblastoma.