DLBCL cells are inhibited by a specific SYK inhibitor with different sensitivities. (A) The IC₅₀ values of PRT318 for DLBCL cell lines were determined using the MTT assay over a wide range of concentrations. (B) Bar graphs and tables showing precise values of IC₅₀ for the cell lines. Error bars show means ± SD of results from 3 independent experiments. (C) PRT318 inhibits growth of the sensitive cell lines in a dose-dependent manner. Two sensitive (LY7 and LY18) and 2 resistant (LY3 and LY4) cell lines were treated with indicated doses of PRT318. The -fold increase in cell number indicates viable cell number at the indicated time point relative to time 0.