UCNP NaYF4:Yb,Tm@NaGdF4:Yb were conjugatedwith poly(ethylene imine) in order to act as gene nanocarriers.649 The optogenetic activation of photoreceptors Arabidopsis flavoprotein cryptochrome 2 (Cry2), the photoreceptorof blue light which interacts with its partner Cib1 activating apoptoticsignaling pathways in cancer cells. Here, CRY2 is linked to cancer.