Background The protein meflin encoded by ISLR contains a C2-type immunoglobulin (Ig)-like domain and five leucine-rich repeat (LRR) domains. ISLR is known to play a role in a small number of tumors, but its role in most tumors is unknown. The purpose of this study was to analyze the expression and prognosis of ISLR in pan-cancer, as well as its correlation with tumor immunity. Methods We used multiple databases and R software to conduct bioinformatics analysis to explore the predictive role of ISLR in pan-cancer, mainly involving expression patterns, prognosis, and immune infiltration. Results Compared with normal tissues, the expression of ISLR was significantly increased or decreased in most tumors. Moreover, the high expression of ISLR may cause the prognosis of some tumors to become better or worse. ISLR also affects immune infiltration in a variety of tumors, which affects the clinical prognosis. ISLR is also significantly related to TMB and MSI in pan-cancer and is related to genes encoding immune regulatory genes. ISLR also affects various cancer-and immune-related pathways. Conclusions ISLR is differentially expressed in tumors, may regulate TME, affect tumor prognosis, and is expected to become a prognostic biomarker.

Background: Pyruvate dehydrogenase protein X (PDHX) is a non-catalytic subunit of the pyruvate dehydrogenase (PDH) complex. It is located in the center of mitochondrial energy metabolism and is an essential component to maintain the biological activity of PDH complex. The purpose of this study was to explore its expression level in gastric cancer and its relationship with immune infiltration. Methods: Through immunohistochemical analysis of 80 pairs of gastric cancer tissue samples and open database analys such as Kaplan-Meier Plotter, TIMER2.0,GEPIA,String and DAVID database.Results: We found that the expression of PDHX in paracancerous tissues was significantly higher than that in gastric cancer tissues. Database analysis showed that the expression of PDHX was low in gastric cancer tissues, and the total survival time (OS) of relatively high expression in gastric cancer patients was higher. In N1~N3 and M stages, the P values of OS and PFS with high expression of PDHX were less than 0.05. It is suggested that the overexpression of PDHX may affect the prognosis of gastric cancer patients with lymph node and distant metastasis. Conclusions: Therefore, we concluded that the expression of PDHX is suppressed in gastric cancer and has a longer overall survival time of 5 years in patients with relatively high expression, and that the increased expression of PDHX may improve the prognosis of patients with lymph node and distant metastasis of gastric cancer.