Figure 12. ROR1 expression in cells and exosomes. (A, B) ROR1 mRNA and protein levels were significantly up-regulated in EGFR-TKIs resistant cells (PC9/GR and HCC827/ER), *p<0.05, **p<0.01 versus matched sensitive cells (PC9 and HCC827). (C, D) ROR1 mRNA and protein expression levels in exosomes were significantly lower than those in cells. *p<0.05, **p<0.01 versus cells.