MRL proteins interact directly with Profilin, Ena/VASP and the Scar/Wave complex via a number of proline-rich regions present in their C-terminal regions.9, 10, 11, 12, 33 To test whether these regions of Pico might be necessary for promoting invasion of RasV12 tumours, we expressed a truncated version of pico encoding only its central RA-PH domain (picoRA-PH). Here, RPS4X is linked to neoplasm.