Many members of the mucin family are evolutionarily conserved and are often 
aberrantly expressed and glycosylated in various benign and malignant 
pathologies leading to tumor invasion, metastasis, and immune evasion. The large 
size and extensive glycosylation present challenges to study the mucin structure 
using traditional methods, including crystallography. We offer the hypothesis 
that the functional versatility of mucins may be attributed to the presence of 
intrinsically disordered regions (IDRs) that provide dynamism and flexibility 
and that the IDRs offer potential therapeutic targets. Herein, we examined the 
links between the mucin structure and function based on IDRs, posttranslational 
modifications (PTMs), and potential impact on their interactome. Using 
sequence-based bioinformatics tools, we observed that mucins are predicted to be 
moderately (20%-40%) to highly (>40%) disordered and many conserved mucin 
domains could be disordered. Phosphorylation sites overlap with IDRs throughout 
the mucin sequences. Additionally, the majority of predicted O- and N- 
glycosylation sites in the tandem repeat regions occur within IDRs and these 
IDRs contain a large number of functional motifs, that is, molecular recognition 
features (MoRFs), which directly influence protein-protein interactions (PPIs). 
This investigation provides a novel perspective and offers an insight into the 
complexity and dynamic nature of mucins.