For example, IntClust 3 has low genomic instability and a high frequency of PIK3CA mutations, IntClust 6 has amplification of 8p12 with upregulation of ZNF703, a common Luminal B BC oncogene11 and IntClust 2 has high genomic instability and amplification of 11q13/14. Here, PIK3CA is linked to breast cancer.