Subsequently, in colorectal carcinoma cell lines, expressing neither constitutive nor inducible CYP1A1,14 CYP2W1 was found to bioactivate 5F 203 and structurally related 2‐(3,4‐dimethoxyphenyl)‐5‐fluorobenzothiazole (GW 610); stable knockdown of CYP2W1 gene led to significant loss of benzothiazole (GW 610, 5F 203) activity in KM12 and HCC 2998 CRC cell lines.22 The gene discussed is CYP2W1; the disease is colorectal carcinoma.