Polr2k, also known as RNA polymerase II subunit K, is a component of the RNA polymerase II complex. This complex is crucial for transcribing DNA into messenger RNA, thus playing a fundamental role in gene expression, a process vital for various biological functions and the normal operation of cells [4,5,6].

In various disease-related studies, Polr2k has emerged as a potentially important gene. In nonspecific orbital inflammation (NSOI), it was identified as one of the seven purine metabolism-related genes (PMGs) closely associated with the disease. Functional analyses indicated its possible involvement in processes like peroxisome targeting sequence binding, seminiferous tubule development, and ciliary transition zone organization, and it showed promising diagnostic capabilities in differentiating NSOI from non-affected states [1].

In chronic kidney disease (CKD), Polr2k was screened from the co-expression network in peripheral blood mononuclear cells (PBMC), and its correlation with clinical parameters such as serum creatinine levels and estimated glomerular filtration rate demonstrated its clinical relevance [2].

In Parkinson's disease, through integrated analysis of single-cell RNA sequencing and bulk transcriptome data, Polr2k was identified as one of the pyroptosis-related diagnostic genes, and a diagnostic model based on it showed good performance [3].

In pneumonia, it was determined as an important protein-encoding gene in the protein-protein interaction (PPI) network constructed from predicted target genes of differentially expressed miRNAs [4].

In hepatocellular carcinoma (HCC), POLR2K was among the genes involved in transcription and protein biosynthesis that were up-regulated [6].

In mantle cell lymphoma (MCL), POLR2K was identified as a hub gene in the top weighted network, and the blue module containing it might play a vital role in MCL pathogenesis [7].

In colorectal cancer, POLR2K was identified as a hub gene among the HSF4 methylation-related genes, with HSF4 methylation potentially being one of the ways to mediate the CRC process [8].

In breast cancer, POLR2K was ranked as one of the best cancer immunotherapy-related proteins predicted by a model using molecular descriptors and artificial neural networks [9].

In conclusion, Polr2k, as an important part of the RNA polymerase II complex, is involved in fundamental gene-expression processes. Its role in various diseases such as NSOI, CKD, Parkinson's disease, pneumonia, HCC, MCL, colorectal cancer, and breast cancer has been revealed through multiple studies. These findings contribute to a better understanding of the molecular mechanisms of these diseases and may potentially lead to new diagnostic and therapeutic strategies.