CALD1 and cancer: Future research aspects may include (1) clinical data about the relationship between expression of the two isoforms in cancers (primary and metastasis) and patient survival; (2) the effects of the expression of upregulated or downregulated isoform in cancers (primary and metastasis) on cell motility and invasive characteristics; and (3) evidence-based clinical studies or animal models on the role of caldesmon in gastrointestinal motility disorders are critically required.