GATA3 and cancer: In METABRIC-(LumA) this produced a total of 772 subgroupings across the 38 cancer genes with at least 20 mutated samples, of which 217 were subgroupings of PIK3CA, 105 were subgroupings of TP53, and 101 were subgroupings of GATA3 (see Additional file 2: Tables S1 for a complete list of enumerated subgroupings).