Sentence:  IL-1β presents the peculiarity of being produced in the form of a biologically inactive precursor, known as proIL-1β, that needs to be <WSD>clived</WSD> at an aspartate residue by a specific enzyme, named interleukin-1β converting enzyme (ICE) or [...] 
Meaning of the word marked with <WSD> tags:  To split; separate; cleave; chop.