EZN4150 reduced P-Akt in MDA-MB-361, BT474 and SKBR3 cells, but did not affect P-Akt in PTEN-deficient HCC1937 cells, consistent with previous observations that PTEN-deficient breast cancer cells preferentially rely on p110β, not p110α, for type I PI3K signaling [3, 7]. This evidence concerns the gene PTEN and breast carcinoma.