GPC4 and lung adenocarcinoma: Opposite results, with a positive association between GPC4 gene expression levels and patient survival, were observed in lung adenocarcinoma (TCGA-LUAD) and two different kidney cancers, kidney renal clear cell carcinoma (TCGA-KIRC) and kidney renal papillary cell carcinoma (TCGA-KIRP) (Figure 2A, bold).