PIK3CD and breast cancer: Among them, 2,4-difluoro-N-(5-(4-((1-(2-hydroxyethyl)-1H-pyrazol-4-yl)amino)quinazolin-6-yl)-2-methoxypyridin-3-yl)benzenesulfonamide (DHW-208) (Fig. 1a) showed optimal anti-breast cancer activity and significant inhibitory activity against four main subunits of PI3K (p110α/p85α, p110β/p85α, p120γ, p110δ/p85α).