CYP26B1 and cancer: Moreover, CYP26B1 expression was inversely correlated with HRD (homologous recombination deficiency) scores in BLCA and BRCA (Figure 5F), while in other cancer types like BRCA and colon adenocarcinoma, CYP26B1 expression was positively correlated with MSI (microsatellite instability) scores (Figure 5G).