The MCF7 ErbB signaling network map.

<p>Σ-states are summations over specific membrane-localized species with identical downstream signaling activity and membrane-anchorage. ΣA:P3-A, ΣA-G, A-ΣG-O, ΣA-G-O, A-ΣG, ΣI:E_ijI, ΣAP-I, ΣG:E_ijG, ΣSP-G, ΣS:E_ijS, ΣAP-S, ΣR:E_ij, ΣAP-R, ΣT:E_ijT, ΣAP-T, ΣO:ΣG-O, A-ΣG-O, ΣA-G-O, E:EGF, H:HRG, E_i:ErbB, G:Grb2, S:Shc, I:PI3K, T:PTP1-B, O:SOS, A:Gab1, R:RasGAP, RsD:Ras-GDP, RsT:Ras-GTP, P2:PIP2, P3:PIP3, E_ij:ErbB homo- or heterodimer bound, E_ijX: E_ij bound to protein. Single-sided solid-head arrows with solid lines depict chemical transformation, while those with dotted lines depict a potentially multistep chemical reaction process. Single-sided double solid-head arrows depict summation into a Σ-state. P denotes tyrosine phosphorylation, PT denotes threonine/serine phosphorylation, and *denotes activation. Red arrows show the targets of ERK, Akt, and ErbB inhibitors.