Conversely, another study showed that Treg levels present in renal cancer tumours did not predict survival,157 with a third study finding that an increased number of Tregs predicted improved survival in Hodgkin lymphoma patients.158,159 The inconsistencies in the data from these studies may be due to the differences in cancer types or the methodology used in these studies used to identify Tregs using Foxp3 expression.153‐158 Not all Foxp3-expressing cells are functional Tregs.160 Thus, without a functional test, inaccuracies in identifying Tregs may occur. This evidence concerns the gene FOXP3 and Hodgkins lymphoma.