CA9 and non-small cell lung carcinoma: The mean value of CAIX in plasma obtained from NSCLC tumours inferior to 1 cm (n=29) was 28.22 pg ml–1 and remained significantly higher when compared with the mean value of CAIX in plasma obtained from the control group (2.48 pg ml–1, n=58, P=0.004) (Figure 2C).