RB1 gross alterations were found in 15% of 433 BLRB and 6.5% of 262 ULRB patients—these patients developed fewer tumours compared to those with null mutations and interestingly, those with cytogenetic or sub-microscopic whole gene deletions often had ULRB, however all those with gross deletions with one breakpoint inside the RB1 gene had BLRB [63]. This evidence concerns the gene RB1 and neoplasm.