This activates the NOTCH pathway, closely associated with B-cell malignancies, contributing to tumor progression in DLBCL.[12] The KMT2C gene, part of the histone methyltransferase family, catalyzes methylation of histone H3 lysine 4 (H3K4), a modification linked to gene activation. Here, KMT2C is linked to diffuse large B-cell lymphoma.