CDKN2A and carcinoma: Within the subgroups of p16INK4a-negative and p16INK4a-positive carcinomas, patients with low proliferation activity as measured by Ki-S5 immunostaining had a lower median survival as compared to those with a high proliferation (p16INK4anegative, Ki-S5 low: 11.1 months, Ki-S5 high: 20.4 months; p16INK4apositive, Ki-S5 low: 37.2 months, Ki-S5 high: 46.9 months) activity (Figure 2B).