Abstract Background HER2-positive patients comprise approximately 20% of breast cancer cases. with HER2-targeted therapy significantly improving progression-free and overall survival. However. subsequent reprogramed tumor progression due to PI3K signaling pathway activation by PIK3CA mutations and/or PTEN-loss cause anti-HER2 resistance. https://safeersappliancers.shop/product-category/neff-b58ct68h0b-n90-slide/