VL exhibit uniquely directed propagation and steering capacity. (a) VL directionality with respect to the radial axes of symmetry. (i) Schematic of radial axes (black arrows) spanning between the nucleus (dark blue oval) and the cell periphery and lateral axes that are oriented orthogonally to each radial axis. (ii) Schematic and corresponding frequency of three directional classifications of pore-closing VL and two for gap-closing VL (iii). n > 10. (b) Example of pore closure by multiple distinctly directed VL (arrowheads). (c) Percentage of VL that travel parallel, antiparallel, or lateral with respect to T cell migration direction. n > 35. (d) The frequency of ∼45°, ∼90°, and ∼180° turns during VL propagation. n > 100. (e) VL steering (cyan arrowheads/lines) during successive diapedesis pore/gap (yellow lines) closures. (f) Complex independent directionality of multiple VL (cyan arrowheads/lines) during closure of concomitantly formed diapedesis pores and gaps (p and g, dashed yellow lines). (b–d) See Video 4. Bars, 5 µm.