RNA samples from HeLa cells were analyzed by microarray expression profiling 24 hours after transfection with the indicated siRNA reagents. Decreases in mRNA levels are shown in green and increases in red. The left panel shows a typical off-target signature of a “Scramble” control siRNA. The right panel shows the off-targets for ON-TARGETplus Non-Targeting Control siRNAs 1 through 4. (D-001810-01, -02, 03, 04).