Using mass spectrometry, immunohistochemistry and immunoelectron tomography, we found that NLRP1 localized to mast cell granules in all MSPC lesions but also in healthy skin, a novel finding which implicates these cells in NLRP1-associated responses in human skin. Here, NLRP1 is linked to corneal intraepithelial dyskeratosis-palmoplantar hyperkeratosis-laryngeal dyskeratosis syndrome.