Okay, the user wants me to translate "skin lightening" into Simplified Chinese. Let me think about the correct term here. "Skin lightening" is commonly referred to as "美白" in Chinese, which directly translates to "whitening" or "lightening of the skin." I should make sure there's no alternative term that's more appropriate. Since the user specified Simplified Chinese, "美白" is the correct form. Also, checking if the original content was already in Simplified Chinese, but since the input was in English, I need to provide the translation. No explanations, just the result. So the answer should be "美白".