Figure 6.

Low IF velocity results in non-metastatic behavior. The zoomed cell velocity field is similar to Fig. 4 but now with a much lower IF velocity. (a) Net cell velocity ${\mathbf{u}}_{\text{c}}$ reflects a uniform, collective downstream migration that sets a large portion of the primary tumor in motion. (b) Cell velocity ${\mathbf{u}}_{c,\text{dispersion}}$ (9) which generates a spreading of tumor cells is small. (c) Cell velocity ${\mathbf{u}}_{c,\text{fluid}-\text{stress}}$ reflects upstream migration but is weak at tumor periphery (dark blue color) due to low IF velocity ${\mathbf{u}}_{\text{w}}$ which largely dictates ${\mathbf{U}}_{\text{T}}$ involved in (8). (d) The cell velocity component ${\mathbf{u}}_{c,\text{chemotaxis}}$ represented by (10) reflects a strong collective downstream migration at the tumor periphery.