Remarkably, the co-inoculated CAF3 survived in large numbers in tumors together with carcinoma cells for periods of up to 29 weeks after injection, as determined by immunohistochemistry using an antibody specific for human vimentin (Figure 9B) and α-SMA (Figure 9B), which MCF-7 cells fail to express. Here, ACTA1 is linked to carcinoma.