Inhibition of Mer expression results in increased chemosensitivity in 697 cells. Wild-type, shControl, and Mer knockdown (shMer1A, shMer1B) 697 cells were treated with the indicated concentrations of 6-mercaptopurine (6-MP), methotrexate (MTX), vincristine (VCR), etoposide (VP-16), or doxorubicin (DOXO) for 48 hours, and relative cell numbers were determined. Mean values and standard errors from at least 3 independent experiments performed in triplicate are shown. IC₅₀ values were determined by nonlinear regression of data from at least 3 independent experiments performed in triplicate (see Table 1).