MEF2C is required for B-cell proliferation and survival after antigen receptor stimulation (Wilker et al, 2008), and MEF2B is frequently mutated in diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (Mahrour et al, 2008; Morin et al, 2011; Ying et al, 2013), but the extent to which MEF2 family transcription factors are modulated by BCR-induced PTMs was not fully known. Here, MEF2B is linked to diffuse large B-cell lymphoma.