Oncohistones are defined as histone mutations that lead to oncogenic features upon expression. Despite the polygenic nature of human histone genes and the fact that oncohistone mutations often affect only one allele of multiple histone genes, oncohistones have been shown to act in a dominant-negative manner to promote oncogenesis. While early studies of oncohistones focused on H3 mutations that alter the landscape of histone modifications, recently characterised oncohistones have been shown to perturb processes beyond histone modifications. This dissertation focuses on H2BG53D (H2B Gly53-to-Asp) found mainly in pancreatic ductal adenocarcinoma (PDAC). Initial structural analysis revealed H2BG53 locates at the site of strong histone-DNA interaction, where RNAPII pauses during transcription. Therefore, it is hypothesised that substitution of the neutrally charged glycine weakens the local histone-DNA interaction and thus alters transcription. Subsequent in vitro assays revealed higher RNAPII passaging in the H2BG53D nucleosome than the wildtype nucleosome. Supporting the in vitro data, H2BG53D expression in the pancreatic cancer cell line showed that H2BG53D induces transcriptional alterations (RNA-seq, PRO-seq) that correlate with the H2BG53D-nucleosome enrichment in the chromatin. Based on gene ontologies, up-regulated genes in H2BG53D cell lines are enriched in migration-related pathways, in line with cell-based assays showing a gain in migration potential. Additionally, ANXA3 was identified as one of the up-regulated genes responsible for the gain in oncogenic features. ANXA3 depletion by shRNA partially reversed the oncogenic potential of H2BG53D cell lines. Moreover, H2BG53D enrichment at the ANXA3 locus was validated by ChIP-qPCR, suggesting that H2BG53D has a direct role in the transcriptional up-regulation of ANXA3. To summarise, this dissertation characterises the oncogenic role of H2BG53D in PDAC, providing evidence for establishing H2BG53D as a novel oncohistone.