RB1 and pachyonychia congenita: Furthermore, reduction in the CN of TP53 as well as RB1 and BRCA2, which are suggested to be major factors in PC carcinogenesis and progression,24 was shown to be associated with poor survival, while only two (1.6%) of 126 patients with localized PC were suggested to have heterozygous or homozygous TP53 deletions.