PTEN and gastric neoplasm: As illustrated in Figure 3, it has been validated that PTEN is an efficient downstream of miR-19a/b in gastric tumour cells, displaying that miR-19a/b aids in alleviating the susceptibility to doxorubicin by downregulating the PTEN and subsequent phosphorylation of AKT, contributing to the suppression of Bax and Caspase-3 together with an increment of the cytotoxic drug efflux by intensifying the expression of P-pg (Wang et al., 2013).