An anti-CSF1R antibody and/or a PD-1/PD-L1 inhibitor for use in a method of treating cancer in a subject; wherein said method comprises concurrently or sequentially administering to said subject an anti-CSF1R antibody and a PD-1/PD-L1 inhibitor; and wherein: the anti-CSF1R antibody is selected from: a) an antibody comprising a heavy chain comprising the sequence of SEQ ID NO: 39 and a light chain comprising the sequence of SEQ ID NO: 46; b) an antibody comprising a heavy chain comprising a heavy chain CDR1 having the sequence of SEQ ID NO: 15, an HC CDR2 having the sequence of SEQ ID NO: 16, and an HC CDR3 having the sequence of SEQ ID NO: 17, and a light chain comprising a light chain CDR1 having the sequence of SEQ ID NO: 18, a LC CDR2 having the sequence of SEQ ID NO: 19, and a LC CDR3 having the sequence of SEQ ID NO: 20; and c) an antibody comprising a heavy chain comprising the sequence of SEQ ID NO: 53 and a light chain comprising the sequence of SEQ ID NO: 60, and the PD-1/PD-L1 inhibitor is an anti-PD-1 antibody selected from: a) an antibody comprising a heavy chain comprising the heavy chain variable region of nivolumab and a light chain comprising the light chain variable region of nivolumab; and b) an antibody comprising a heavy chain comprising the heavy chain CDRs of nivolumab, and a light chain comprising the light chain CDRs of nivolumab. the anti-CSF1R antibody is selected from: a) an antibody comprising a heavy chain comprising the sequence of SEQ ID NO: 39 and a light chain comprising the sequence of SEQ ID NO: 46; b) an antibody comprising a heavy chain comprising a heavy chain CDR1 having the sequence of SEQ ID NO: 15, an HC CDR2 having the sequence of SEQ ID NO: 16, and an HC CDR3 having the sequence of SEQ ID NO: 17, and a light chain comprising a light chain CDR1 having the sequence of SEQ ID NO: 18, a LC CDR2 having the sequence of SEQ ID NO: 19, and a LC CDR3 having the sequence of SEQ ID NO: 20; and c) an antibody comprising a heavy chain comprising the sequence of SEQ ID NO: 53 and a light chain comprising the sequence of SEQ ID NO: 60, and a) an antibody comprising a heavy chain comprising the sequence of SEQ ID NO: 39 and a light chain comprising the sequence of SEQ ID NO: 46; b) an antibody comprising a heavy chain comprising a heavy chain CDR1 having the sequence of SEQ ID NO: 15, an HC CDR2 having the sequence of SEQ ID NO: 16, and an HC CDR3 having the sequence of SEQ ID NO: 17, and a light chain comprising a light chain CDR1 having the sequence of SEQ ID NO: 18, a LC CDR2 having the sequence of SEQ ID NO: 19, and a LC CDR3 having the sequence of SEQ ID NO: 20; and c) an antibody comprising a heavy chain comprising the sequence of SEQ ID NO: 53 and a light chain comprising the sequence of SEQ ID NO: 60, and the PD-1/PD-L1 inhibitor is an anti-PD-1 antibody selected from: a) an antibody comprising a heavy chain comprising the heavy chain variable region of nivolumab and a light chain comprising the light chain variable region of nivolumab; and b) an antibody comprising a heavy chain comprising the heavy chain CDRs of nivolumab, and a light chain comprising the light chain CDRs of nivolumab. a) an antibody comprising a heavy chain comprising the heavy chain variable region of nivolumab and a light chain comprising the light chain variable region of nivolumab; and b) an antibody comprising a heavy chain comprising the heavy chain CDRs of nivolumab, and a light chain comprising the light chain CDRs of nivolumab.