[Hopeful]

Lest anyone be too geeked out, here is the guts of the thing:

"The central finding of this work is that tumor growth and invasion are not erratic or unpredictable, or solely explained through genomic and molecular events, but rather are predictable processes obeying biophysical laws, driven by microenvironmental substrate gradients, and regulated by genotypic, phenotypic, and microenvironmental parameters (e.g., cell adhesion, proliferation, and motility). The model enables quantitative study of invading cell clusters as functional units that move as complex systems. Substrate gradients, e.g., of nutrient, oxygen, growth factors, and metabolites, result from diffusion, cellular activity, and heterogeneous delivery and removal. This leads to local hypoxia, nutrient starvation, acidosis, necrosis, and the pleiomorphic appearance of tumors. The underlying physical mechanism of collective cell migration, i.e., a gross tumor morphologic instability (2, 8–10, 12–14, 40), maximizes cell exposure to substrates by evading a compact, nearly spherical morphology in favor of infiltrating shapes moving up gradients of substrates such as oxygen. Phenotypic changes that increase nutrient uptake and augment cell proliferation (and also increase cell motility and reduce adhesion) have a quantifiable effect on morphology at the tumor scale. In particular, they trigger invasive fingering into host tissue while inducing necrosis and angiogenesis for certain parameter conditions. <sup>"

Hopeful</sup>