CSF1R and cancer: <h4>Background</h4>Tumour associated macrophages (TAMs) and exhausted T cells are dominant in the immuno-suppressive tumour microenvironment (TME) and pose a challenge to effective cancer immunotherapy in solid tumours.<h4>Methods</h4>In this study, we immunised llamas and generated monovalent and biparatopic nanobodies (Nbs) against colony stimulating factor 1 receptor (CSF-1R) and programmed death receptor 1 (PD-1) to re-educate TAMs and overcome T cell exhaustion, respectively, in the TME.