几率比例？ 大体了解是用来比较你的东西和在另一个东西中的enrichment。
例如，我有ATAC-seq differential peak， 想知道enrichment 在cell type enhancer data set里面的情况，这样根据OR就能知道，在哪些cell type的enhancer cluster中是highly enriched 了。
Odds ratios are used to compare the relative odds of the occurrence of the outcome of interest (e.g. disease or disorder), given exposure to the variable of interest (e.g. health characteristic, aspect of medical history). The odds ratio can also be used to determine whether a particular exposure is a risk factor for a particular outcome, and to compare the magnitude of various risk factors for that outcome.
OR=1 Exposure does not affect odds of outcome
OR>1 Exposure associated with higher odds of outcome
OR<1 Exposure associated with lower odds of outcome
