Together with our findings demonstrating increased CD45RA:ERK association in myeloma cells, these results raise the possibility that CD45RA localized outside of lipid rafts attenuates K-ras-triggered ERK activation by facilitating CD45RA:galectin-1:fibronectin interaction and thus induction of P21, P27 and subsequent inhibition of CdK2 activity and myeloma cells growth inhibition. This evidence concerns the gene FN1 and plasma cell myeloma.