GMO Cells contain information about an entity type, but also already have a set Gene.
Each GMO Cell has its own recipe, allowing you to skip the grinding process of randomly getting a specific Gene normally.
For example, a Potion of Mutation combined with a Netherite Pickaxe can be combined in a low temperature Advanced Incubator to have a chance of getting the Haste II Gene.
For a full list of GMO recipes you can either use EMI, or check the default GMO recipes page.