Mitochondrial biogenesis is crucial for the fast growth of cancer cells. In parallel, nuclear-encoded mitochondrial ribosomal proteins are highly expressed in cancer, where the insertion of H2A.Z, a histone variant, at the target genes plays a critical role in gene activation. EP400 is an epigenetic enzyme that has been implicated in H2A.Z insertion and transcription regulation. Here, I will present recent progress on EP400NL, a pseudogene-like variant gene that evolved from EP400 and participates in H2A.Z histone exchange and upregulation of Myc target genes. Additionally, I will introduce a potential application of a peptide display platform using synthetic nanofibers for peptide vaccine, PD-L1 biomarker diagnostics, and DNA vaccine delivery.