What I would really like to see in such cases is not so much other people simply trying to reproduce the results, but an investigation into why one group got different results. Certainly it could be for a scientifically uninteresting reason -- ranging from outright fraud, to sloppy experimental technique causing contamination, to arithmetic errors in analyzing the results -- but it could also be for a scientifically interesting reason: perhaps they used cells from a different supplier that differ in some relevant property that nobody had previously noticed, for example.
In short, there might be some interesting discovery to be had, buried underneath the discrepancy. I hate to see us overlook that possibility in our haste to get the "right" answer.