Our study discerned that miR‐21‐related genes, such as ABCB1, SPRY1, ERGE, PIK3R1, SPTBN1, VIM, and others, which experienced downregulation in tumor sites, exhibited a negative correlation with tumor purity and a positive association with T cell infiltration, notably CD8+ T cells. Here, ABCB1 is linked to neoplasm.