Tumor Immune infiltration estimation showed that the expression levels of COL3A1, RAC1, FN1, and SDC2 were all negatively associated with tumor purity whereas positively correlated with CD4+ T cells (Figure 6A) in PCa, as indicated that these proteins may be expressed in this type of immune cells rather than in tumor cells. The gene discussed is SDC2; the disease is posterior cortical atrophy.