TGFB1 and melanoma: Similarly, an in vivo pooled knock-in screen which assessed the relative genotype abundance of 36 synthetic receptors, transcription factors and metabolic regulators among melanoma-infiltrating lymphocytes (TILs), found that introduction of a novel chimeric TGF-β-R2-41BB receptor endowed T cells with the capacity to resist immunosuppressive signaling from TGF-β leading to enhanced melanoma clearance in vivo (55).