MKI67 and lipoma: To analyze whether the effects seen in the WST-1 assays are caused by an inhibition of proliferation, we counted Hoechst-stained nuclei of lipoma cells after alpelisib, rapamycin, or combined treatment (Figure 2a–d) and performed immunofluorescence staining of the proliferation marker Ki-67 in LipPD1 cells after 48 h alpelisib treatment (Figure 2e–f).