Toward the trend of theranostic technologies, a closed‐loop microneedle system (IWCS) has been developed for wearable diagnosis and treatment of diabetes, enabling in situ glucose detection and insulin delivery (Figure 6d).[40] The IWCS is composed of three connected components: a reverse iontophoresis‐combined microneedle sensor, a flexible printed circuit board, and a microneedle iontophoresis‐assisted transdermal drug delivery system (Figure 6e). The gene discussed is INS; the disease is diabetes mellitus.