Gelderblom H, et al. - Nilotinib, a colony-stimulating factor 1 receptor (CSF1R) tyrosine kinase inhibitor, was tested for safety and efficacy in patients with locally advanced non-resectable pigmented villonodular synovitis. Achievement of disease control was noted with 12 weeks of nilotinib treatment in more than 90% of patients with locally advanced unresectable progressive pigmented villonodular synovitis. With manageable toxicity, anti-tumour activity of CSF1R tyrosine kinase inhibitors was indicated in patients with inoperable progressive pigmented villonodular synovitis.