SIX2 expression was associated with poor RFS in NSCLC (pooled HR = 1.31, 95 % CI, 1.06–1.63, p = 0.331, and I2 = 13.1 %; Fig. 7a) as well as in ADC (pooled HR = 1.42, 95 % CI, 1.14–1.77, p = 0.610, and I2 = 0.0 %; Fig. 7b). Here, SIX2 is linked to non-small cell lung carcinoma.