COL6A1 and cancer: We first performed intrinsic expression analysis, and our results demonstrated that the gene expression levels of COL6A1/2/3 were relatively higher than 2, whereas the expression levels of other COL6A members (COL6A4/5/6) were less than 1 in pan-cancer, indicating that the expression levels among different COL6A members showed a remarkably heterogeneous distribution.