Validation of myeloma survival kinases. (A) Top-ranked kinases targeted by lethal siRNA during primary high-throughput screens were tested in KMS11 cells using 4 unique siRNAs per kinase, assayed individually in separate wells, to verify survival kinase identification and to exclude kinases falsely identified during primary screening by chance or by off-target siRNA effects. As not all siRNAs efficiently silence their target, only the top 3 of 4 siRNAs tested are shown. The effects on viability of siRNAs are shown in arbitrary relative units, with UBB siRNA inducing approximately 100% cell death. To exclude false positives, only kinases whose targeting yielded concordant lethal results from ≥ 3 of 4 unique siRNAs were considered validated survival kinases. For validated survival kinases, the median viability loss induced by all siRNAs tested is shown as a bar. (B) XY plot of kinase gene mRNA expression in KMS11 and INA6 versus kinase siRNA lethality during primary kinome screening. Kinase mRNA levels were determined by Affymetrix (U133_2+ chip) expression profiling and represent the mean signal intensity (MAS5) of all probe sets per gene. Validated survival kinases are labeled.