In MIcγ1 and BIcγ1 mice, markers of exhaustion/activation (Pdcd1, Tigit, Lag3) and cytotoxicity (Ifng, Gzma, Gzmb, Gzmk) were similarly expressed by CD8+ T cells at MM states, but these were barely detected in MGUS samples. Here, CD8A is linked to Miyoshi myopathy.