Next generation sequencing analysis also found higher penetrance mutations in breast cancer 1 (BRCA1), tumour protein p53, mitogen-activated protein kinase 1 (MAP3K1), retinoblastoma 1 (RB1), phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) and GATA binding protein 3 (GATA-3) genes that results in breast cancer formation [18, 19]. This evidence concerns the gene RB1 and breast cancer.