Current knowledge in this field seems to affirm that patients with the KIAA1549-BRAF fusion seem to respond better to MEK inhibitors than the ones that are BRAF-fused negative (32), as in our patient ́s case, whereas paradoxical reactions to BRAF inhibitors with tumor accelerated growth has been reported in these BRAF-fused patients (21, 34, 35). The gene discussed is MAP2K7; the disease is neoplasm.