CDKN1B and lung adenocarcinoma: As shown in Figure 1(D) and Table 1, p27Kip1 expression showed a significant inverse correlation with EGFR expression in lung adenocarcinoma specimens (Spearman correlation: rs=−0.360; P=0.019), colorectal cancer specimens (Spearman correlation: rs=−0.359; P=0.018) and bladder cancer specimens (Spearman correlation: rs=−0.337; P=0.039), strongly suggesting that p27Kip1 expression might be involved in the regulation of EGFR expression.