Fig. 1

Collagen XIII expression is increased during breast cancer development. a Western blot analysis of Collagen XIII (Col13) in the malignant and non-malignant mammary epithelial cell lines in vitro. Red stands for triple negative breast cancer cell lines, blue stands for luminal type breast cancer cell lines, black stands for non-malignant mammary epithelial cell lines. b Col13 mRNA expression in human breast cancer and normal mammary tissues in the TCGA dataset. n = 593 ** p < 0.01. c Col13 mRNA expression in human breast cancer and normal mammary tissues in the Finak dataset. n = 59 ** p < 0.01. d Col13 mRNA levels in ER negative (n = 91) and ER positive (n = 270) subgroups of breast cancer patients; ** p < 0.01. e Col13 mRNA expression in triple negative breast cancer tissues (n = 48) and other subtypes (n = 473); results are presented as the mean ± s.e.m.; ** p < 0.01. f Kaplan-Meier analysis of recurrence free survival of breast cancer patients grouped into high and low expression levels of Col13. The patients were equally divided into two groups based on the mRNA levels of Col13 in breast cancer tissues, n = 3554; *** p < 0.001. g Kaplan-Meier analysis of recurrence free survival of estrogen receptor negative patients grouped into high and low expression levels of Col13. n = 671; *** p < 0.001