383As regards the product market, it is clear from the case-law of the Court of Justice that the concept of the relevant market implies that there can be effective competition between the products or services which form part of it and this presupposes that there is a sufficient degree of interchangeability between all the products or services forming part of the same market in so far as a specific use of such products or services is concerned. Interchangeability or substitutability is not assessed solely in relation to the objective characteristics of the products and services at issue The competitive conditions and the structure of supply and demand on the market must also be taken into consideration (judgment of 23 January 2018, F. Hoffmann-La Roche and Others, C‑179/16, EU:C:2018:25, paragraph 51 and the case-law cited).