KMT2D and mature T-cell and NK-cell non-Hodgkin lymphoma: The genes most frequently observed to be altered in PTCL are represented by KMT2D (H3K4 methyltransferase), KMT2A (H3K4 methyltransferase), SETD2 (H3K36 methyltransferase), KDM6A (H3K27 demethylase), CREBBP (H3K18 acetyltransferase), EP300 (H3K18 acetyltransferase), and EZH2 (H3K27me3 reader) [111,112,113,114].