CD44 and neoplasm: They exhibit numerous advantages,including easy synthesis, facile chemical modification, good stability,and ease of combination with other strategies, giving peptides a significantedge in tumor-targeting therapies.48−51 A6 peptide (KPSSPPEE) is a urokinase-derivedpeptide with a high binding affinity to CD44 and shows effective inhibitionof the growth and metastasis of CD44-overexpressing tumors.52−55 Moreover, A6 exhibits an exceptional safety profile after subcutaneousadministration.56 Thus, A6 could serveas a superior specific binding moiety to target tumors with CD44 overexpression.