Lowercase the string entered in Python

warn_investment_list = ["Microsoft", "Google", "Naver", "Kakao", "SAMSUNG", "LG"]

word = input ("input: ")

if word in warn_investment_list:
    print ("This is an investment warning stock")
else:  
    print ("Not an investment warning stock")

=============================================================================== This code says that if you enter Microsoft, it is not an investment warning item.

To recognize even when entering lowercase letters like Microsoft

Should I write word.lower?