Evidence has emerged that bone marrow cells have a greater degree of plasticity than previously thought. However, there has been a call to establish proof that these bone marrow-derived cells function appropriately in their new environment. We have already shown that the bone marrow contributes to myofibroblasts in multiple organs and that this is exacerbated by injury and occurs in a mouse tumor model. Here, we provide evidence that these cells are functioning appropriately by showing that bone marrow-derived myofibroblasts are expressing mRNA for the alpha(1) chain of type I (pro)collagen using a new customized technique. This provides evidence that the bone marrow-tumor stroma axis is functionally relevant and may therefore subsequently be exploited to develop new strategies for anticancer therapy.