Raloxifene , an anti-osteoporotic drug , is recently approved for prevention of breast cancer in postmenopausal women and thus the drug may be employed to combat the bony adverse effects of letrozole , another anticancer drug .
Combined Raloxifene and Letrozole for Breast Cancer Patients.  Raloxifene , an anti-osteoporotic drug , is recently approved for prevention of breast cancer in postmenopausal women and thus the drug may be employed to combat the bony adverse effects of letrozole , another anticancer drug . However, the cytotoxic effect of their combination on human breast cancer (MCF-7) and human embryonic kidney (HEK) cell lines is not known. MCF-7 and HEK cell lines were treated with different graded doses of letrozole, raloxifene and their combination, then incubated for 24-48 h. MTT assay was performed to check the cytotoxicity of the drugs. The study indicates that the combination of letrozole and raloxifene possess additive effect in terms of cytotoxicity of cancer cell lines (MCF-7) and negligible effects in normal cell lines (HEK). Our study indicates that the addition of raloxifene doesn't interfere with anticancer efficacy of letrozole rather the combination acted additively for the treatment of breast cancer.
### Instruction:
            Given the context about compound efficacy for the given treatment mentioned within the input, mentioned the compounds 
            that can co-occur for the mentioned treatment

            ### Input:
            Combined Raloxifene and Letrozole for Breast Cancer Patients.  Raloxifene , an anti-osteoporotic drug , is recently approved for prevention of breast cancer in postmenopausal women and thus the drug may be employed to combat the bony adverse effects of letrozole , another anticancer drug . However, the cytotoxic effect of their combination on human breast cancer (MCF-7) and human embryonic kidney (HEK) cell lines is not known. MCF-7 and HEK cell lines were treated with different graded doses of letrozole, raloxifene and their combination, then incubated for 24-48 h. MTT assay was performed to check the cytotoxicity of the drugs. The study indicates that the combination of letrozole and raloxifene possess additive effect in terms of cytotoxicity of cancer cell lines (MCF-7) and negligible effects in normal cell lines (HEK). Our study indicates that the addition of raloxifene doesn't interfere with anticancer efficacy of letrozole rather the combination acted additively for the treatment of breast cancer.

            ### Response:
            Raloxifene, letrozole
            