hsa-mir-4423: Hsa-mir-4423 is a sequence feature that enhances Drosha-mediated processing and is found downstream of one third of all human conserved miRNA stem-loops [44, 47]. The CNNC motif, which is bound by SRSF3, a major auxiliary factor for pri-miRNA processing, plays a role in the productive processing of hsa-mir-4423 by Drosha in the presence of SRSF3 [112, 113]. Hsa-mir-4423 is currently only annotated in the genomes of humans and chimpanzees and has been identified as a regulator of airway epithelial cell differentiation and a repressor of lung carcinogenesis [36, 115]. The efficiency of hsa-mir-4423 processing by Drosha is influenced by MS risk variants [PMC9111935]. The MS risk allele A of SNP rs817478 confers a much lower hsa-mir-4423 processing efficiency compared to the MS risk allele T [PMC9111935]. The C allele creates a CNNC motif downstream of hsa-mir-4423, whereas the motif is missing when the more common MS risk allele A is present [PMC9111935]. The miRTarBase database currently contains no miRNA-target interaction with strong evidence for hsa-mir-4423 except for TMEM47 as its potential direct target gene [78, PMC9111935]. Further research is needed to understand how genetic factors interact with environmental and lifestyle factors to alter miRNA maturation and function [125, 126].