HIF1A and colorectal carcinoma: To test whether the suggested link between metastasis formation, hypoxia and CD44 (most likely isoform 3, as this was the most abundant isoform, see above) could also be established in clinical samples, we stained consecutive slides of primary CRC specimens and matched liver metastases for HIF‐1α and CD44v9 (isoform 3 contains v8‐v10).