LGR5 is an established stem cell marker in a number of murine tissues (Leung et al, 2018; Haegebarth and Clevers, 2009; Nusse and Clevers, 2017), is overexpressed in a range of cancers (Morgan et al, 2018; Yamamoto et al, 2003; McClanahan et al, 2006; Tanese et al, 2008; Hagerling et al, 2020; Nakata et al, 2013; Cosgun et al, 2017, 2020), and studies using genetically engineered mouse models (GEMMs) and human CRC organoids have found that LGR5 is critical for maintaining the proliferative compartment in tumours (Junttila et al, 2015; Gong et al, 2016; Morgan et al, 2018). The gene discussed is LGR5; the disease is colorectal carcinoma.