TGFB1 and follicular lymphoma: Furthermore, in the setting of Follicular lymphoma, TGFβ secretion by both tumour cells and T-cells within the surrounding TME have been reported to cause Treg expansion (Yang et al., 2013), suppression of helper T-cell generation (Yang et al., 2013) and induction of T-cell exhaustion (Yang et al., 2014), which is associated with poorer survival outcomes (Yang et al., 2014).