Based on the findings in pancreatic and colorectal cancers that demonstrate the ability of VD to inactivate CAFs and return them to a more quiescent phenotype [103,106], a recent study trialed a new approach to target CAFs in BC using FAP-coated nanoparticles loaded with the VD analog, calcipotriol (FAP-C NPs) [108]. Here, FAP is linked to breast cancer.