25746
Five chemicals were used : two compounds known to react with cysteine residues , 2 , 4 - dinitrochlorobenzene ( DNCB ) and cinnamaldehyde ( CinA ) ; one sensitizer known to exhibit mixed reactivity to cysteine and lysine residues , isophorone diisocyanate ( IPDI ) ; and one reacting specifically with lysine residues , trimellitic anhydride ( TMA ) and croton oil a well - known irritant .
 cysteine, 2 , 4 - dinitrochlorobenzene, DNCB, cinnamaldehyde, CinA, cysteine, lysine, isophorone diisocyanate, IPDI, lysine, trimellitic anhydride, TMA
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: Chemical 
Text: {0} 
Answer:
 cysteine, 2 , 4 - dinitrochlorobenzene, DNCB, cinnamaldehyde, CinA, cysteine, lysine, isophorone diisocyanate, IPDI, lysine, trimellitic anhydride, TMA