The PI3K pathway is activated in <i>Apc</i>^<i>Min/+</i>, <i>Fc</i>^<i>+</i> <i>Pik3c</i>a^<i>p110*</i>, and <i>Fc</i>^<i>+</i> <i>Pik3ca</i>^{<i>H1047R</i>} mice.

<p>Immunoblotting demonstrates robust phosphorylation of AKT in <i>Apc</i>^<i>Min</i>, <i>Fc</i>^<i>+</i> <i>Pik3c</i>a^<i>p110*</i> and <i>Fc</i>^<i>+</i> <i>Pik3ca</i>^{<i>H1047R</i>} colon tumors (A). Increased phosphorylation of RPS6 and 4EBP1 beyond that seen in the <i>Apc</i>^<i>Min</i> lesions is observed in the <i>Fc</i>^<i>+</i> <i>Pik3ca</i>^{<i>H1047R</i>} and <i>Fc</i>^<i>+</i> <i>Pik3c</i>a^<i>p110*</i> colon tumors. The more aggressive phenotype seen in the <i>Fc</i>^<i>+</i> <i>Pik3c</i>a^<i>p110*</i> mice, with a greater number and decreased latency, is associated with an increased phosphorylation of 4EBP1 compared to <i>Fc</i>^<i>+</i> <i>Pik3ca</i>^{<i>H1047R</i>} tumors (B).