Multiple researchers and investigators determined the potent role of thymoquinone in combination with cyclophosphamide by applying different concentrations (0.5 mM‐10 μM) against Her2 + breast cancer cells through inhibiting the proliferation through the accumulation of cells in sub‐G1 (5.49%) and G1 (57.72%), whereas 12% cells were shifted from G2/M phase. The gene discussed is ERBB2; the disease is breast cancer.