Plots of within-chip log amplitude z-scores for two more HG-U133ASpike-in Experiment "Unanticipated Positives". These are two more genes which are not in the Affymetrix original list of spiked-in genes, and which were considered for inclusion by McGee and Chen but ultimately rejected. 203173_s_at (shown on the left) is similar in profile to 204890_s_at and 204991_s_at. The profiles are somewhat different for 203060_s_at (on the right), but still do not appear to be compatible with the hypothesis that they come from probe sets with identical probe-level distributions for experimental conditions 1 (cyan) and 14 (red). These genes are also obvious unanticipated positive candidates.