LTF and specific granule deficiency: This includes proteins abundant in the matrix of secondary granules [lactoferrin (LTF), neutrophil gelatinase-associated lipocalin (LCN2), transcobalamin-1, and olfactomedin-4 (OLF4)], tertiary granules (neutrophil collagenase, arginase-1) and subtypes of primary granules (neutrophil defensin 1) in neutrophils and in the matrix of eosinophilic granules (arachidonate 15-lipoxygenase (ALOX15), eosinophil major basic protein homolog/proteoglycan 3) in SGD (Table 1).