Wojdak-Maksymiec et al. (2013) reported that allele T of the gene TNF-α was associated with a lower number of mastitis cases in lower parities and a higher number of mastitis cases in higher parities. Similarly, the causal variants or genes could be different for susceptibility to – and recoverability from mastitis as association signals present on the same chromosome do not overlap. Our results support the findings that QTLs even for highly correlated traits (e.g., SCC and CM) present on the same chromosome do not overlap (Sender et al., 2013). Here, TNF is linked to mastitis.