Analysis of mRNA expression of MDR1, MRP, cMOAT and β2m genes using RT-PCR. Lane (N) is negative control, without cDNA, and lane (P) is positive controls, K562/ADM for MDR1 and β2m, HepG2 for MRP and cMOAT. Lanes 1 through 3, 4 through 9, 10 through 12 and 13 through 14 are NK cells from the normal donors, indolent NK-GLPD, aggressive NK cell tumors, and NK cell lines, respectively. Lanes 4 through 12 correspond to patients 1 through 9 of Table 1, respectively. Lane 13 is the cell line NK92, and lane 14 is the cell line NKL.