The function of CHIT1 (chitinase 1, ENSG00000133063) is as follows. Degrades chitin, chitotriose and chitobiose. May participate in the defense against nematodes and other pathogens. Isoform 3 has no enzymatic activity. {ECO:0000269|PubMed:7592832, ECO:0000269|PubMed:7836450}.