Another study that employed quantum dot (QD)‐labeled EGF in combination with hidden Markov modeling revealed longer lifetimes of EGFR:EGF dimers and a variation across different cell lines, with 3.59 s in the epidermoid carcinoma cell line A431, 13.02 s in HeLa cells, and 8.33 s in EGFR‐transfected CHO cells.[57, 58] The longer lifetimes might be related to the larger QD labels, which exhibit outstanding brightness yet might also impede receptor mobility and subsequent processing steps of ligand‐activated receptors. This evidence concerns the gene EGF and squamous cell carcinoma.