DBCO-PEG2-Val-Cit-PAB-MMAE is an ADC linker featuring a DBCO group, a Val-Cit dipeptide, a PAB moiety, and an MMAE payload. The DBCO group serves as a click chemistry handle that can react with azide groups, while the Val-Cit dipeptide is protease-cleavable, enabling the release of the MMAE payload into cells through an elimination mechanism.