TKT and neoplasm: In agreement with a reduced tumor burden, ganciclovir-treated HSV-TK/Col1 + KRasLA2 mice showed significantly decreased numbers of proliferating cells, blood vessels (Supplementary Fig. 3C), fibroblasts, fibrocytes and macrophages in the tumor niches, accompanied by reduced M2-like macrophage and increased M1-like macrophage markers (Supplementary Fig. 3D, E), all compared with KRasLA2 and KRasLA2 + ganciclovir control mice.