Interestingly, down-regulation of Lyn activity does not influence STAT3 and ERK activation in CD45+ myeloma cells [8], and the inhibition of ERK activity using ERK inhibitor or siRNA has no effect on the phosphorylation of STAT3 in INA-6 myeloma cells [12], suggesting that there are no cross talk among these three pathways. Here, PTPRC is linked to plasma cell myeloma.