While the majority of the paradoxical genes are novel and their association with LUAD prognosis has not been investigated thoroughly, there are 17 validated paradoxical genes that have been previously associated with prognosis of other cancers: ADAM28 [35, 36], ANGPT1 [37], CA2 [38], CA24 [39], DAB2 [40], HOXA5 [41, 42], IL6 [43], KLF10 [44], MCL1 [45], NES [46], NUSAP1 [47], PDZD2 [48], RGS17 [49, 50], RUNX1T1 [51, 52], SELC14L1 [53], SEMA5A [54] and SEPP1 [55] (Table 2). This evidence concerns the gene CA2 and cancer.