SMAD1 and diffuse large B-cell lymphoma: In diffuse large B-cell lymphoma (DLBCL), DNA hypermethylation at the SMAD1 promoter leads to SMAD1 and subsequent surface receptor sphingosine 1 phosphate receptor 2 (S1PR2) loss, a process that is reversible by treatment with hypomethylating agents (43, 49).