RB1 and neoplasm: Losses in chromosome regions of well-known tumour suppressor genes like BRCA1, BRCA2, BRIP1, CDH1, CHEK2, PTEN, RB1 and TP53 were found in 18 (16.9%), 3 (2.7%), 16 (14.2%), 12 (10.6%), 10 (8.8%), 17 (15.0%), 11 (9.7%) and 4 (3.5%) tumours, respectively.