Expression level of p16 is not affected by p16 methylation. (A) Gene expression profile between patients with methylated p16 (n = 14, mean normalized expression 0.31 ± 0.24) and unmethylated p16 (n = 32, mean normalized expression 0.31 ± 0.26). The normalized expression level p16 is similar when compared by Student t test (P = .49). (B) Quantitative RT-PCR was performed on 7 patients with p16 methylation, 11 without p16 methylation, and 5 normal unmethylated plasma cells samples. Fold change analysis relative to normal unmethylated plasma cells using the ΔΔCT method showed once again there is no difference in p16 expression between patients with and without p16 methylation as detected by MS-PCR (1.87 ± 0.43 versus 1.56 ± 0.59, P = .70, t test).