hsa-mir-4640: Hsa-mir-4640 is a microRNA (miRNA) that has been found to have a disruptive potential on miRNA function due to a novel "CT" deletion [PMC4159108]. This deletion has been observed in 7 out of 14 globally diverse populations and alters the predicted mRNA targets of hsa-mir-4640 [PMC4159108]. The deletion adds 3 additional targets and removes all of the original 79 predicted targets from regulation [PMC4159108]. MiRNA target prediction was done with and without the "CT" deletion using DIANA prediction software [PMC4159108]. In the absence of the mutation, the 3' strand of hsa-mir-4640 was predicted to target 316 binding sites in 79 genes [PMC4159108]. Furthermore, this "CT" deletion has been found in individuals from various populations, including Pygmy, Sandawe, Yoruba, Maasai, African-Americans, Mexican-American, and Gujarati Indian individuals [PMC4159108]. In addition to hsa-mir-4640, other miRNAs such as hsa-miR-520a-5p, hsa-miR-214-3p, and hsa-miR-525-5p have also been found to be related to overall survival using Kaplan Meier plotter software [PMC7757131]. Moreover, low expression levels of certain miRNAs including hsa-mir-4640 have been associated with a higher survival rate [PMC8321750]. Overall, these findings highlight the importance of understanding the disruptive potential of genetic variations on miRNA function and their impact on overall survival.