Traditionally, the macroevolutionary trends were explored by paleobiology, comparative morphology and evo-devo approaches. Recently, genomic phylostratigraphy, a new approach, has appeared on these trends, with the cumulative increase of genomic data. It can contribute to analyses for phylotypic stage in the relationship between phylogeny and ontogeny, as well as cancer studies. The paper presents the core of phylostratigraphy and its significance for ontogeny and cancer research.