If your P value looks too good to be true, it probably is: Communicating reproducibility and variability in cell biology

Cell biology is littered with erroneously tiny P values, often the result of evaluating individual cells as independent samples. Because readers expect low P values and small error bars to imply that an observed difference would persist if the experiment were to be duplicated, the sample size (N) used for statistical tests should actually be the number of times an experiment was repeated. P values calculated using the number of cells do not reflect the reproducibility of the result and are thus highly misleading. To help authors avoid this mistake, we provide examples and practical tutorials to create figures that communicate both the cell-level variability and the experimental reproducibility.