The function of H1-4 (H1.4 linker histone, cluster member, ENSG00000168298) is as follows. Histone H1 protein binds to linker DNA between nucleosomes forming the macromolecular structure known as the chromatin fiber (PubMed:35581345, PubMed:40240600). 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:35581345, PubMed:40240600, PubMed:40516528). Ability to associate with nucleosomes and compact chromatin depends on linker DNA length and trajectory (PubMed:35581345). Also acts as a regulator of individual gene transcription through chromatin remodeling, nucleosome spacing and DNA methylation (PubMed:40240600). {ECO:0000269|PubMed:35581345, ECO:0000269|PubMed:40240600, ECO:0000269|PubMed:40516528}.