Hi! I'm using tximport to summarize transcript-level abundance to get gene-level abundance. I didn't specify a value to 'abundanceCol', and I got an abundance matrix in the result. I wonder what's the default value of 'abundanceCol'. Thanks!

The default is dependent on the input. Mostly it's TPM, but for e.g., StringTie it's FPKM. You can always see the function body by typing the function name at the command prompt.