Cancer researchers tend to use the cancer effect size to determine the relative importance of the genetic alterations that confer selective advantage to cancer cells.
Cancer biology is finding genetic alterations that confer selective advantage to cancer cells.  Cancer researchers have frequently ranked the importance of substitutions to cancer growth by P value. P values are thresholds for belief, not metrics of effect. 
FindingGeneticAlterationsConferSelectiveAdvantageCancerCells(cancerBiology)  PValue(cancerResearchers, theImportanceOfSubstitutionsToCancerGrowth)  ∀x (PValue(x) → ThresholdsForBelief(x) ∧ ¬MetricsOfEffect(x))