• Its disruption blocks alternative lengthening of telomeres (ALT) activity and leads to extensive telomere shortening in ALT+cancer cell lines (Barroso-González et al., 2019) • RAD51AP1 silencing suppresses the epithelial-mesenchymal transition (EMT) and metastasis of non-small cell lung cancer (NSCLC) (Wu et al., 2019). This evidence concerns the gene RAD51AP1 and cancer.