RB1 and chronic cystitis: This study explored the role of p53, p16, bcl-2, ki-67, c-myc, Rb and EGFR, by using Immunohistochemistry assay, in 45 SBT and 39 NSBT patients in comparison with 16 schistosomal chronic cystitis (SC), 28 non-schistosomal chronic cystitis (NSC), and 20 normal control (CTL) subjects.