HTR6 and lung carcinoma: In addition, pallidol was shown to inhibit protein kinase C activity [30], suppressed the growth of lung cancer cells A549 [46], and exerted effects on 5-hydroxytryptamine 6 receptor-mediated Ca2+ responses and extracellular-signal-regulated kinases (ERK)1/2 phosphorylation as 5-hydroxytryptamine 6 receptor antagonists [70].