Among all the immunocytes, CD56 (dim) natural killer cells were most positively correlated to MBD3 (r = 0.38), and immature B cells were most negatively correlated to NTHL1 (r = −0.38), which indicated that the number of immune cells in MM patients is affected by differentially expressed m5C regulators. This evidence concerns the gene MBD3 and Miyoshi myopathy.