CFTR and cystic fibrosis: In the following year (2011), the same team reported that quercetin dissolved in DMSO is an activator of ciliary beat frequency (CBF) in primary cultures derived from individuals with functional CFTR but not in cultures from patients homozygous for the ΔF508 mutation.[19] In detail, quercetin increased CBF in normal but not in CF human sinonasal epithelial cultures.