sentence: Immunofluorescent staining confirmed the absence of DRC1 , DRC2 and DRC4 in respiratory tract cilia from Drc1 and Drc1 mice ( Fig. 7 and Supplementary Material , Fig. S13 ) , whereas RSPH9 signal intensity was unchanged in these cilia , suggesting that the RS structure was unaffected by DRC1 deletion in respiratory tract cilia .