Western blot analysis of downstream targets of MAP3K7. (a) Western blot analysis reveals reduced phosphorylation of NF‐kB upon overexpression of most CSCF‐causing (black circles) and some FMD2‐causing (blue circles) MAP3K7 mutations in HEK‐293T cells, compared to MAP3K7WT. N = 7 for all conditions except for WT (N = 10). (b) Western blot analysis of phospho‐ERK1/2 (pERK) reveals reduced phosphorylation of ERK1/2 upon overexpression of most CSCF‐causing MAP3K7 mutations compared to MAP3K7WT, except for MAP3K7Arg83His. N = 4 for all conditions, except for WT (N = 8). Error bars represent standard error of the mean. *p < 0.05; ***p < 0.0001. Mutations in bold indicate the known mutations. CSCF, cardiospondylocarpofacial syndrome; ERK, extracellular signal‐regulated kinase; FMD2, frontometaphyseal dysplasia type 2; GAPDH, glyceraldehyde 3‐phosphate dehydrogenase; MAP3K7, mitogen‐activated protein 3 kinase 7; NFκB, nuclear factor‐κB;pNFκB, phospho‐NFκB; WT, wild‐type.