x1 = PPase
x2 = S2_n
x3 = pS2_n
x4 = G_n
x5 = pG_n
x6 = S22_n
x7 = S24_n
x8 = S4_n
x9 = G2_n
x10 = G4_n
x11 = GG_n
x12 = S22_c
x13 = S24_c
x14 = S4_c
x15 = S2_c
x16 = pS2_c
x17 = G_c
x18 = pG_c
x19 = G2_c
x20 = G4_c
x21 = GG_c
x22 = TGFb_c
x23 = R_act
x24 = R
x25 = R_inact
x26 = SB