As shown in Table 2, increased level of Hsp90-beta was observed in MPE of the 107 lung cancer patients (2.01 ± 0.66 ng/mL) compared with pleural effusion of the 50 control individuals (1.21 ± 0.42 ng/mL) (P < 0.001) (Fig. 1a). This evidence concerns the gene HSP90AB1 and Pleural effusion.