SIK1 and infection: In addition, immunofluorescence demonstrated that while single ad-SIK1 infection did not alter the cytoplasm-dominant distributions of SIK1, CRTC2, and SREBP-1c, treatment with HG-9-91-01 alone significantly promoted the nuclear import of these molecules, CRTC2 being the most evident example, and the addition of ad-SIK1 did not seem to modify the nuclear localization induced by HG (Figure 4G).