GATA3 and breast carcinoma: Notably, both low GATA3 protein (Bergen cohort I) and mRNA levels (METABRIC cohorts II–III) are significantly associated with the group of young breast cancer patients (below 40 years), with tumors more frequently having low GATA3 compared to breast cancer patients ≥40 years (p < 0.001; Table 1; supplementary material, Table S1).