Such epigenetic markers promote GLI-1 occupation of ABCG2 gene promoter sequences and induce the expression of ABCG2, which is involved in chemoresistance in the presence of doxorubicin and methotrexate in non-solid tumors and B-cell non-Hodgkin lymphoma cells [38]. This evidence concerns the gene ABCG2 and B-cell non-Hodgkin lymphoma.