Therefore, in our continuous search of the cytotoxic candidates from Cameroonian plants with unpublished ethnopharmacological information related to cancer use, we investigated the antiproliferative potential of six Cameroonian plants against cancer cell lines with different mechanisms of drug resistance, that is, ATP-binding cassette (ABC) transporters (P-glycoprotein, breast cancer resistance protein), tumor suppressors (p53), or oncogenes (epidermal growth factor receptor). This evidence concerns the gene ABCG2 and cancer.