KCNRG and astrocytoma (excluding glioblastoma): Additionally, changes in gene expression were investigated by qPCR, and transcription factor binding sites were analyzed in the CiiiDER program.<h4>Results</h4>For the first time, our results indicate that calcitriol directly affects the activity of the mitochondrial large-conductance Ca<sup>2+</sup>-regulated potassium channel (mitoBK<sub>Ca</sub>) from the human astrocytoma (U-87 MG) cell line but not the mitochondrial calcium-independent two-pore domain potassium channel (mitoTASK-3) from human keratinocytes (HaCaT).