Abstract
Transposable elements (TEs) are dispersed repetitive DNA sequences that can move within a genome. Even though hundreds of years of evolution have led to the accumulation of mutations that render most TEs unable to transpose, they still exert multiple important functions. They play a role in hematopoiesis, especially during periods of high cellular plasticity, such as development, regeneration and aging. This is because TEs can populate functional elements, such as enhancers. Furthermore, TE RNA can be sensed by innate immune sensors that play a role in inflammation and inflammaging. TEs also play an important role in different aspects of leukemia and lymphoma, leading to either beneficial or detrimental outcomes. Further studies into the function of TEs in healthy or diseased hematopoietic systems are necessary to manipulate them for therapeutic benefit.