I am writing on behalf of the Gene Disruption Project to report a revision in the insertion site data for the P-element insertion stock EY03976 (FBst0015698).  We reported that this stock had two P-element insertions on 3L at  3L:3460603..3460603  (R5) and  3L:6970284..6970284  (R5).  This was based on recovery by inverse PCR of a 5prime flank mapping to the former site and a 3prime flank mapping to the other site.  However, when the inverse PCR was repeated after the third chromosome was balanced, only the 3prime flank mapping to  3L:6970284..6970284  was recovered. When I reexamined the original inverse PCR data, I realized that the 5prime sequence was the same as that of a sample in an adjacent well on the 96 well plate.  It is therefore likely that this 5prime flank was a cross-contamination artifact and that EY03976 has a single insertion at  3L:6970284..6970284  (R5).