Stem Cell Hierarchy and Clonal Evolution in Acute Lymphoblastic Leukemia

Figure 2

Treatment escape leading to relapse in the stem cell and clonal evolution models. In the cancer stem cell model, all leukemic bulk cells are eradicated by therapy, apart from stem cell-like LICs, which are resistant to therapy and give rise to relapse. In the clonal evolution model, distinct subclones acquire the capability of therapy resistance by ongoing mutations. Subclones that were not eradicated during therapy provide then the leukemic reservoir for relapse.