Figure 4.

Mammary acinus as an example of a ‘functional tissue unit’, μ(s), the level at which ductal carcinoma as a system emerges. Again, the red box area highlights the levels of importance in an emergence framework. The logical components, C_a(s), of the ‘functional tissue unit’ are the tissue components at the level below, Level n + 2. Components at lower levels are important only through the impact they have on the components, C_a(s), by changing the components themselves and/or changing the structure, S_c(s). Physiological changes alter the environment, E_b(s), or mechanism, M_d(s).