All 4 hepatic hemangiosarcomas had a CAG to CTG transversion at codon 61 of the human c-H-ras gene, but no point mutations were detected in codon 61 of the mouse c-H-ras gene.
Forestomach squamous cell carcinomas, lung adenocarcinomas and spleen angiosarcomas were induced by dimethylbenzanthracene (DMBA) in the rasH2 transgenic mouse line carrying human c-Ha-ras genes with their own promoter, encoding the prototype p21 gene product.
Over half of the angiosarcomas (n = 18, 53%) harbored genetic alterations affecting the MAPK pathway, involving mutations in KRAS, HRAS, NRAS, BRAF, MAPK1 and NF1, or amplifications in MAPK1/CRKL, CRAF or BRAF.