EGFR and colorectal carcinoma: Furthermore, Rac1b is required for oncogenic Wnt signalling, as well as for the resultant tumour initiation phenotype that follows Apc loss in vivo. Importantly, depletion of RAC1B re-sensitised EGFR inhibitor-resistant human CRC organoids derived from liver metastases to EGFR inhibition (Gudino et al., 2021b).