RB1 and neoplasm: This type of RB1 deletions was found primarily in the unilateral patients of our cohort, which agrees with the hypothesis of DiCiommo et al. [29], who stated that the genes that neighbor RB1 may be vital for the cell and if their deletion is followed by a second LOH RB1 mutation, the cell could not survive, thus the tumor transformation would occur in only a few cells.