The percentage of p16-immunolabeled cells was scored using a four-class digressive scale from score 0 to score 3: expression in more than 50 % of tumour cells (score 0), from 50 to 11 % (score 1), in 10 % or less (score 2), or total absence of p16-expression (score 3). The gene discussed is CDKN2A; the disease is neoplasm.