ENPP2 and neoplasm: With regard to the other markers, platelet count <20 × 104/μL (sensitivity 95.5%; specificity 44.6%), M2BPGi >1 (sensitivity 79.1%; specificity 45.9%), and ATX >1 (sensitivity 64.0%; specificity 52.3%) might be used in addition to regular follow‐up with ultrasonography and/or tumor markers.