MUC5AC and melanoma: In another study, H. aspersa mucin directly inhibited the growth of two human melanoma cell lines, by increasing expression of the cytokine TNFα, and inhibiting NF-κB, a transcription process that in proper regulation has been linked to cancer progression, the growth of these cell lines was decreased, demonstrating its anti-melanogenic properties (Domínguez-Martín et al., 2020).