python使用regex提取大写单词

cell cells

([A-Z][^ ]*)(?=\s+(?:[^A-Z]\S*\s+){1,4}cells?)

input = "Briefly, MCF-7 idential cells grown as described above were treated with a range of LTX-diol or iso-LTX-diol."

r1 = re.findall(r"([A-Z][^ ]*)(?=\s+(?:[^A-Z]\S*\s+){1,4}cells?)", input)
print(r1)

['MCF-7']