The function of Ensembl gene identifier ENSG00000124575 (H1-3, H1.3 linker histone, cluster member) is as follows. Histone H1 protein binds to linker DNA between nucleosomes forming the macromolecular structure known as the chromatin fiber (PubMed:37922872). Histones H1 are necessary for the condensation of nucleosome chains into higher-order structured fibers and promote formation of the H3K27me3 mark by the PRC2/EED-EZH2 complex (PubMed:40516528). Together with histone H1-3, histone H1-3 acts as a regulator of splicing, most specifically exon skipping and intron retention events: histone H1-3 has a high affinity for introns and regulates splicing by affecting RNA polymerase II (RNAPII) elongation (PubMed:37922872). Also acts as a regulator of individual gene transcription through chromatin remodeling, nucleosome spacing and DNA methylation (By similarity). {ECO:0000250|UniProtKB:P43277, ECO:0000269|PubMed:37922872, ECO:0000269|PubMed:40516528}.