The function of HELLS (helicase, lymphoid specific, Ensembl gene identifier ENSG00000119969) is as follows. ATP-dependent chromatin remodeler that regulates chromatin accessibility, DNA methylation, and histone modifications. It facilitates de novo DNA methylation at repetitive sequences and promotes transcriptional silencing via recruitment of DNA methyltransferases (DNMTs) and histone deacetylases (HDACs), contributing to heterochromatin formation and repression of transposable elements (PubMed:30307408). Also involved in DNA repair by recruiting DNA damage response mediators to double-strand breaks in heterochromatin, promoting homologous recombination via RBBP8/CtIP- dependent end resection (PubMed:22946062, PubMed:31802118). During meiosis, it is recruited by PRDM9 to recombination hotspots, aiding chromatin opening (PubMed:32001511). Through these diverse roles, is crucial for processes such as development, differentiation, and genomic stability (PubMed:22946062, PubMed:31802118). Involved in regulation of the expansion or survival of lymphoid cells (By similarity). {ECO:0000250|UniProtKB:Q60848, ECO:0000269|PubMed:22946062, ECO:0000269|PubMed:30307408, ECO:0000269|PubMed:31802118, ECO:0000269|PubMed:32001511}.