MUC1 and breast cancer: Mucin 1 (or MUC1), a glycosylated protein present on the epithelial cell surface, has been shown to participate in the progression and metastasis of different cancers, including colon carcinoma, ovarian malignancy, renal tumors, breast cancer, and lung carcinoma.[264] Consequently, a large number of aptamer‐based sensors have been developed in recent years for MUC1 detection.[265] Among these, several sensors have been successfully deployed for MUC1 detection in serum with good sensitivity and specificity.