all指代Mucins还是The core？

Large airways are completely lined by a mucous layer, whereas in smaller, more distal airways the mucus is found in ‘islands’, and a mucous layer is absent in small bronchioles and beyond. Mucus is 97% water, and about one-third of the remaining 3% is glycoproteins called mucins,6 which determine the viscoelastic and other properties of the mucus. The human genome encodes 17 mucins, of which only seven are secreted, while the remainder are membranebound mucins.4Mucin is released by rapid (,150 ms) exocytosis from the mucous-secreting goblet cells in response to a range of stimuli, including direct chemical irritation, inflammatory cytokines and neuronal stimulation, predominantly by cholinergic nerves. Mucins have a core composed of glycoprotein subunits joined by disulphide bonds, and their length may extend up to 6 µm. The core is 80% glycosylated, with side chains attached via O-glycosidic bonds. Almost all terminate in sialic acid and possess microorganism binding sites. Mucus plays a vital role in pathogen entrapment and removal, and also has a variety of antimicrobial actions (see later).

大气道完全被黏液层覆盖，而在较小的、更远端气道中，黏液呈“岛”状分布，而小的细支气管及其远端气道中没有黏液层。黏液中97%是水，约1%中是黏蛋白（糖蛋白中的一类）6，黏蛋白决定了黏液的黏弹性和其他特性。人类基因组编码17种黏蛋白，其中仅有7种为分泌型黏蛋白，其余均为与膜结合型黏蛋白4。在受到一系列刺激后（包括直接化学刺激、炎性细胞因子及以胆碱能神经为主的神经元刺激等），分泌黏液的杯状细胞通过快速（<150ms）胞吐作用释放黏蛋白。黏蛋白可长达6µm，其80%糖基化的核心由二硫键连接的糖蛋白亚基组成，通过侧链与O-糖苷键连接。几乎全部终止于唾液酸并具有微生物结合位点。黏液对病原体的吞噬和清除十分重要，同时还具有多种抗菌作用（见下文）。

all指代Mucins还是The core？是不是只能指代Mucins？因为要和唾液酸形成联系？谢谢