FOXP3 and diffuse large B-cell lymphoma: the effects of 3 months of selenium intake on the frequency of CD4+CD25+FOXP3+ Treg cells and immune checkpoint receptor expression were investigated in patients with diffuse large B‐cell lymphoma (DLBCL) subtype non‐Hodgkin lymphoma (NHL) 16 patients receiving Se (Se+) and 16 patients not receiving Se (Se−).