concept

γ (promoter stiffness): LEVEL and A4 SHAPE

γ = −mean(ΔG37); A4 = signal − γ

Each master gene is read as a stiffness LEVEL (γ) and an orthogonal SHAPE (A4) — promoter structure only, never a function or a dose.

γ is a measured promoter-structure LEVEL, not a fitted parameter. It is the window-mean of the SantaLucia-1998 nearest-neighbour stacking-stiffness signal; the A4 coordinate is that same signal with the mean removed (the orthogonal SHAPE).

Both are read, because γ alone is lossy: genes with equal γ but different SHAPE are not interchangeable (the A4 tie-break). By the firewall, γ is never a channel gain, a drive, a dose, an in-vivo selectivity, or a clinical effect — all of those are [O].