RT-qPCR analysis revealed a significant downregulation of PTPRCAP mRNA in lung adenocarcinoma tissues (median: 0.107, IQR: 0.053–0.288) compared to matched adjacent non-tumor tissues (median: 1.084, IQR: 0.535–2.166), representing an approximate tenfold decrease (Mann-Whitney U = 257, P < 0.0001; n = 45 patient samples; Fig 1A). The gene discussed is PTPRCAP; the disease is neoplasm.