TFF1 and neoplasm: The fact that TFF1 may contribute to tumor metastasis to bone is proved by its high expression in MBC. Emami et al. explained this by the ability of TFF1 to dimerize with cysteine-rich molecules, as cysteine-rich intestinal protein 1 (CRIP1) which also may be overexpressed in breast cancer and might be an interacting partner for TFF1 [32].