E2F1 and neoplasm: Conversely, the let-7 family, miR-34a, miR-145, and miR-29 targets are regarded as tumor suppressors and can inhibit tumor formation, proliferation, migration, spread, and angiogenesis by targeting many oncogenic transcription factors, including E2F1, K-RAS and c-MYC (Yang et al., 2015; Alizadeh et al., 2019; Zhang et al., 2019; Xu et al., 2020).