  The distribution of Red Blood Cells in a confined channel flow is
inhomogeneous and shows a marked depletion near the walls due to a competition
between migration away from the walls and shear-induced diffusion resulting
from interactions between particles. We investigated the lift of RBCs in a
shear flow near a wall and measured a significant lift velocity despite the
tumbling motion of cells. We also provide values for the collective and
anisotropic shear-induced diffusion of a cloud of RBCs, both in the direction
of shear and in the direction of vorticity. A generic down-gradient
subdiffusion characterized by an exponent 1/3 is highlighted.
