ObjectiveTo analyze the expression and prognostic value of PHD Finger Protein 19 (PHF19) in non-small cell lung cancer (NSCLC) based on gene chip data. MethodsThe data about The Cancer Genome Atlas (TCGA) lung cancer patients were downloaded to analyze the expression of PHF19 in lung cancer. The data sets GSE30219 and GSE50081 were downloaded from the Gene Expression Omnibus (GEO), and the patients were screened into the training set and the validation set respectively, thus analyzing the relationship between PHF19 expression, gender, age, tumor clinical stage, pathological type and disease-free survival (DFS), as well as their relationship with overall survival (OS). Gene Ontology (GO)-Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analysis and immune infiltration analysis were performed on PHF19 and co-expression related genes in lung cancer patients through the online database. ResultsThe data from TCGA and GEO showed PHF19 was highly expressed in lung cancer (P<0.001), and PHF19 expression was related to tumor stage. The NSCLC patients in the PHF19 low expression group had longer DFS and OS than those in the high expression group (P<0.05). Multivariate COX regression analysis showed PHF19 was an independent prognostic factor in NSCLC patients (P<0.05). A nomogram drawing to predict the survival rate of lung cancer patients and verifying the C index showed the model has good accuracy. Gene enrichment analysis showed PHF19 high expression is mainly related to the cell cycle, cell nucleus, chromatin, etc. Immune infiltration analysis showed PHF19 is closely related to immune cell infiltration. ConclusionsPHF19 can be used as an indicator to predict the prognosis of NSCLC. PHF19 high expression is an independent predictor of poor prognosis of NSCLC and may be a new target for its treatment.