COL27A1 and posterior cortical atrophy: Interestingly, among putative targets of let-7d-5p, we found that COL27A1, coding for fibrillar collagen α-1 (XXVII) chain protein and, to our knowledge, never associated with PCa, was the only downregulated gene in PCa patients as reported in The Cancer Genome Atlas (TCGA) compared to controls, suggesting a potential role for this let-7d-5p-target gene in PCa pathogenesis (Table 1, Figure 6B) [41].