Fig. 6

Protein-protein interactions and the causal inference model. a Kaplan–Meier survival plot of the MUC4 gene DSVs. MUC4 (d−) indicates that cancer patients have no MUC4 gene deletion. MUC4 (d+) indicates that cancer patients have the MUC4 gene deletion. RFS indicates recurrence-free survival. The survival analysis showed that patients with MUC4 (d−) had a better clinical outcome (p = 0.027), and colorectal cancer patients with the MUC4 gene deletion were associated with increased immune gene (MAGE1) expression. The right column shows the MUC4 gene deletion and MAGEA1 expression correlation plot (r = 0.35). b The STRING database was used to show protein-protein interactions of the transmembrane mucin family, including MUC1, MUC4, and MAGEA1. c Kaplan–Meier survival plot of CEP72 DSV. CEP72 (d−) indicates that cancer patients have no CEP72 gene deletion. CEP72 (d+) indicates that cancer patients have a CEP72 gene deletion. RFS indicates recurrence-free survival. The survival analysis showed that patients with CEP72 (d+) had a better clinical outcome (p = 0.012), and patients with the CEP72 gene deletion were associated with decreased immune gene (IFIT1) expression. The left figure shows the CEP72 gene deletion and IFIT1 expression correlation plot (r = 0.36). d Causal inference model of DSVs, immune gene expression, and RFS. Gray circles represent DSV genes, white circles represent immune expression genes, and the black circle represents RFS. The arrow indicates the causal effect pair. The red arrow pair indicates the RFS causal inference-associated pairs. The causal inference model showed that CEP72 could affect RFS by IFIT1