YAP1 and cancer: Since CSCs are implicated in the growth, migration, invasion, angiogenesis, anti-cancer drug resistance, and metastasis in MIBC, the influence of Chaga on the expression levels of three important CSC markers, CD44, SOX2, and YAP1 which were upregulated in most of MIBC (Ciamporcero et al., 2016) were examined.