Fig. 4

a Dose response relationship of background corrected HKG MFI values. The horizontal dashed lines indicate the background corrected MFI threshold based on the negative controls. Compound treatments crossing the threshold in a dose dependent manner is indicative for cytotoxicity. b Example of a dose response relationship on FC for a gene of interest after treatment with a specific compound, where normalization failed due to instable HKG. Over correction occurred at the second highest concentration, though not immediately visible from the FC plot (see Fig. 3b) but signals drop far below the negative control levels (a). This compound will be indicated as potential cytotoxic and results should be interpreted with care