X-Axis for Volcano Plot
Use the ratio of the proportions of occurrences on a log2 scale. so that a unit change corresponds to a doubling Use the ratio of the odds of occurrence between two groups on the log2 scale. The Woolf-Haldane estimate of the Odds Ratio is used if any of the table cells are equal to 0.Note: For rare events (occurrences), the odds ratio approximates the relative risk